refactor(server): extract the diagnostics routes into routers/diagnostics.py (R3) (#857)

The three /api/diagnostics/* routes (export, preview, hardware) plus their
exclusive payload-cap helpers and the `_diag_*` normalisers. Bodies verbatim
except @app->@router, CONFIG_DIR->appstate.config_dir, _running_version()->
appstate.running_version() (a new seam slot; the impl stays in server.py where
the settings region also calls it), and the builtin-plugins lookup in
_diag_plugins_roots: Path(__file__).parent -> Path(__file__).resolve().parents[2]
(routers -> lib -> app root; plugins/ ships at the app root in every packaging
path).

The pure caps/normalisers (_diag_cap_console/_dict/_contributions,
_diag_coerce_bool, _diag_normalize_include, _DIAG_MAX_*) are re-exported from
server.py so the existing `server._diag_*` / `server._DIAG_*` tests keep
resolving — none of them monkeypatch these, so no test retargets.

server.py: 7,216 -> 6,960.

Verified: pyflakes clean (bar the intentional re-export lines); route table
IDENTICAL (143); full pytest 2399 passed (77 diag/packaging + 122 diagnostic-
matched cases incl the cap/coerce/normalize suites); eslint 0; Codex pending.
Boot smoke: /hardware, /preview, and POST /export (200 application/zip) all
serve from the new router location.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -27,7 +27,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 - **Perf harness now measures 2D-highway frame time (R3c gate).** `scripts/perf-baseline.mjs` gains a `--song` mode that reports per-frame draw-cost p50/p95/p99 (draw-tagged via `highway.addDrawHook`), the metric that gates the `highway.js` split. Maintainer/CI-only; baseline recorded in `docs/perf-baseline.md`.
-- **`routers/` — extracting `server.py`'s route layer, cheapest-first (R3).** Each PR moves a cohesive route group into a `fastapi.APIRouter` under `lib/routers/`, mounted with `app.include_router(...)` at its original site (FastAPI matches in registration order; the full route table stays byte-identical). Bodies are verbatim — only the decorator receiver (`@app` → `@router`) and singleton reads (`meta_db` → `appstate.meta_db`, resolved at call time) change. So far: `audio_effects` (5), `artist_aliases` (5), `loops` (3), `playlists` (12 + covers), `ws_highway` (the 902-line highway chart WebSocket), `chart` (split/unsplit/work/fileinfo — unblocked by the DLC-path substrate). The DLC library-path resolution (`_get_dlc_dir`, pure `_resolve_dlc_path`) moved to `lib/dlc_paths.py`, reading paths through the seam; `config_dir`/`dlc_dir`/`dlc_dir_env` now ride the `appstate` seam (env-derived, so the pop-and-reimport fixtures reconfigure it for free), and the shared request-field sanitizer `_clean_str` moved to `lib/reqfields.py`. The next cut is picked by a dependency-closure scan that ranks groups by how many `monkeypatch.setattr(server, …)` targets they'd drag along.
+- **`routers/` — extracting `server.py`'s route layer, cheapest-first (R3).** Each PR moves a cohesive route group into a `fastapi.APIRouter` under `lib/routers/`, mounted with `app.include_router(...)` at its original site (FastAPI matches in registration order; the full route table stays byte-identical). Bodies are verbatim — only the decorator receiver (`@app` → `@router`) and singleton reads (`meta_db` → `appstate.meta_db`, resolved at call time) change. So far: `audio_effects` (5), `artist_aliases` (5), `loops` (3), `playlists` (12 + covers), `ws_highway` (the 902-line highway chart WebSocket), `chart` (split/unsplit/work/fileinfo — unblocked by the DLC-path substrate), `library_extras`, `wanted`, `shop`, `progression`, `profile`, `stats` (the `/api/stats/{path}` catch-all stays registered last so it can't shadow `/recent` `/best` `/top`), `version` (`/api/version`; VERSION-file lookup adjusted for the router subdir depth), and `diagnostics` (`/api/diagnostics/export|preview|hardware`; the plugins-root lookup adjusted for the router subdir depth, `_running_version` reached through the `appstate` seam, pure payload-cap helpers re-exported for the `server._diag_*` tests). The DLC library-path resolution (`_get_dlc_dir`, pure `_resolve_dlc_path`) moved to `lib/dlc_paths.py`, reading paths through the seam; `config_dir`/`dlc_dir`/`dlc_dir_env` now ride the `appstate` seam (env-derived, so the pop-and-reimport fixtures reconfigure it for free), and the shared request-field sanitizer `_clean_str` moved to `lib/reqfields.py`. The next cut is picked by a dependency-closure scan that ranks groups by how many `monkeypatch.setattr(server, …)` targets they'd drag along.
 - **`routers/` — the first extracted route module (R3).** The five audio-effects mapping
   endpoints move out of `server.py` into `lib/routers/audio_effects.py` as a
   `fastapi.APIRouter`, mounted with `app.include_router(...)` **at the point in the file

docs/size-exemptions.md

@@ -55,8 +55,8 @@ without a *signed* exemption" is unenforceable.
 ## Planned, NOT exempt (owned by split plans — listed so nothing falls between states)
 
 core `static/app.js` (11,852) · `static/highway.js` (4,168, whole file) · `server.py`
-(7,216 — was 14,037; ratcheted by the R3 `MetadataDB` + `AudioEffectsMappingDB`
+(6,960 — was 14,037; ratcheted by the R3 `MetadataDB` + `AudioEffectsMappingDB`
-extractions and thirteen `routers/` modules) ·
+extractions and fourteen `routers/` modules) ·
 `lib/metadata_db.py` (4,373 — new in R3; the `MetadataDB` class alone is 4,018 lines
 and is a monolith in its own right, to be split per-table once the router train
 lands) · `static/v3/songs.js` (4,134) · `static/capabilities/audio-session.js`

lib/appstate.py

@@ -87,12 +87,14 @@ audio_cache_dir = None
 # in server.py (its `setattr(server, "_progression_content")` test is untouched).
 get_progression_content = None
 builtin_diagnostic_filename = None
+running_version = None
 
 _SLOTS = frozenset({
     "meta_db", "audio_effect_mappings",
     "config_dir", "dlc_dir", "dlc_dir_env",
     "static_dir", "sloppak_cache_dir", "audio_cache_dir",
     "get_progression_content", "builtin_diagnostic_filename",
+    "running_version",
 })
 
 

lib/routers/diagnostics.py

@@ -0,0 +1,295 @@
+"""Diagnostic bundle export + hardware probe (/api/diagnostics/*).
+
+One-click "Export Diagnostics" in Settings produces a redacted zip combining
+server logs, system info, hardware (CPU/GPU/RAM), plugin inventory, and the
+browser-side console transcript + hardware probe. Bundle format is specified in
+docs/diagnostics-bundle-spec.md.
+
+Extracted verbatim from server.py (R3) except:
+  - the decorators (@app -> @router),
+  - CONFIG_DIR -> appstate.config_dir and _running_version() ->
+    appstate.running_version() (both read through the appstate seam),
+  - the builtin-plugins lookup in _diag_plugins_roots: Path(__file__).parent
+    (the app root when this lived at the top level) ->
+    Path(__file__).resolve().parents[2] (routers -> lib -> app root). The
+    plugins/ dir ships at the app root in every packaging path.
+
+The pure helpers + caps here are re-exported from server.py so the existing
+`server._diag_*` / `server._DIAG_*` tests keep resolving (none monkeypatch them).
+"""
+
+import json
+import logging
+import os
+from pathlib import Path
+
+from fastapi import APIRouter, Body, Response
+
+import appstate
+from dlc_paths import _get_dlc_dir
+from diagnostics_bundle import build_bundle as _diag_build, preview_bundle as _diag_preview
+from diagnostics_hardware import collect as _diag_hardware
+from env_compat import getenv_compat
+
+log = logging.getLogger("feedBack.server")
+router = APIRouter()
+
+
+def _diag_log_file() -> Path | None:
+    raw = os.environ.get("LOG_FILE", "").strip()
+    if not raw:
+        return None
+    return Path(raw)
+
+
+def _diag_plugins_roots() -> list[Path]:
+    """Return all plugin root directories for orphan scanning.
+
+    Includes both the built-in ``plugins/`` directory and
+    ``FEEDBACK_PLUGINS_DIR`` when set, so user-installed plugins and
+    orphans in the external dir are reflected in the bundle.
+    """
+    roots: list[Path] = []
+    user_dir = getenv_compat("FEEDBACK_PLUGINS_DIR", "").strip()
+    if user_dir:
+        p = Path(user_dir)
+        if p.is_dir():
+            roots.append(p)
+    builtin = Path(__file__).resolve().parents[2] / "plugins"  # R3: app root from lib/routers/
+    if builtin not in roots:
+        roots.append(builtin)
+    return roots
+
+
+def _diag_coerce_bool(v, *, default: bool = True) -> bool:
+    """Coerce a request-side value to bool, accepting both JSON booleans and
+    string representations.
+
+    - Falsy strings: ``"false"``, ``"0"``, ``"no"``, ``""`` → ``False``
+    - ``None`` → *default*
+    - Everything else (including ``"true"``, ``"1"``) → ``True``
+    """
+    if v is None:
+        return default
+    if isinstance(v, bool):
+        return v
+    if isinstance(v, str):
+        return v.strip().lower() not in ("false", "0", "no", "")
+    return bool(v)
+
+
+def _diag_normalize_include(include: dict | None) -> dict:
+    """Coerce request-side flags to the booleans build_bundle expects.
+    Missing keys default to True so a bare {} request still produces
+    the full bundle.
+
+    Accepts both JSON booleans (``true``/``false``) and string
+    representations so callers that serialize flags as strings behave
+    consistently with the preview endpoint:
+    - Falsy strings: ``"false"``, ``"0"``, ``"no"``, ``""`` → ``False``
+    - Everything else (including ``"true"``, ``"1"``, ``"yes"``) → ``True``
+    """
+    keys = ("system", "hardware", "logs", "console", "plugins")
+    if not isinstance(include, dict):
+        return {k: True for k in keys}
+
+    return {k: _diag_coerce_bool(include.get(k), default=True) for k in keys}
+
+
+# Server-side caps on client-supplied payload sections.  diagnostics.js
+# enforces a 500-entry / ~250 KB ring buffer on the browser side; these
+# bounds give generous headroom while still preventing a crafted POST from
+# forcing the server to allocate arbitrarily large in-memory bundles.
+_DIAG_MAX_CONSOLE_ENTRIES = 1000          # hard cap: truncate silently
+_DIAG_MAX_CONSOLE_BYTES = 2 * 1024 * 1024  # 2 MB hard cap on total console list
+_DIAG_MAX_CLIENT_PAYLOAD_BYTES = 2 * 1024 * 1024   # 2 MB per dict section
+_DIAG_MAX_CONTRIBUTIONS_BYTES = 4 * 1024 * 1024    # 4 MB aggregate cap for contributions
+
+
+def _diag_cap_console(v) -> list | None:
+    """Return *v* if it is a list, truncated to _DIAG_MAX_CONSOLE_ENTRIES entries
+    and _DIAG_MAX_CONSOLE_BYTES total.  Entries are accumulated until either cap
+    is reached; no partial-entry splitting occurs."""
+    if not isinstance(v, list):
+        return None
+    result = v[:_DIAG_MAX_CONSOLE_ENTRIES]
+    # Also enforce a byte cap — the count cap alone does not bound memory when
+    # entries contain arbitrarily large strings.
+    try:
+        out = []
+        total = 0
+        for entry in result:
+            encoded = json.dumps(entry, separators=(",", ":")).encode("utf-8", errors="replace")
+            if total + len(encoded) > _DIAG_MAX_CONSOLE_BYTES:
+                break
+            out.append(entry)
+            total += len(encoded)
+        return out
+    except (TypeError, ValueError):
+        return None
+
+
+def _diag_cap_dict(v) -> dict | None:
+    """Return *v* if it is a dict whose JSON serialisation fits within
+    _DIAG_MAX_CLIENT_PAYLOAD_BYTES, otherwise return None."""
+    if not isinstance(v, dict):
+        return None
+    try:
+        encoded = json.dumps(v, separators=(",", ":")).encode("utf-8", errors="replace")
+    except (TypeError, ValueError) as e:
+        log.warning("diagnostics client payload is not JSON-serialisable, dropping: %s", e)
+        return None
+    if len(encoded) > _DIAG_MAX_CLIENT_PAYLOAD_BYTES:
+        return None
+    return v
+
+
+def _diag_cap_contributions(v, known_ids=None) -> dict | None:
+    """Apply per-plugin and aggregate size caps on client_contributions.
+
+    Unlike _diag_cap_dict(), which drops the whole dict when any plugin
+    exceeds the limit, this function caps each plugin independently so
+    one noisy plugin does not silence every other plugin's contribution.
+
+    Parameters
+    ----------
+    v:
+        The raw contributions dict from the POST payload.
+    known_ids:
+        When provided, contributions from plugins not in this set are
+        skipped *before* serialisation, preventing a malicious caller
+        from forcing the server to JSON-encode hundreds of near-limit
+        payloads that ``build_bundle()`` would later discard anyway.
+        ``None`` means "accept all plugin ids" (used in tests / preview).
+    """
+    if not isinstance(v, dict):
+        return None
+    result = {}
+    total_bytes = 0
+    for pid, contribution in v.items():
+        if not isinstance(pid, str):
+            continue
+        # Filter unknown plugin ids early — before serialising — so a
+        # crafted request cannot force large allocations for plugins that
+        # build_bundle() would drop.
+        if known_ids is not None and pid not in known_ids:
+            continue
+        try:
+            encoded = json.dumps(contribution, separators=(",", ":")).encode("utf-8", errors="replace")
+        except (TypeError, ValueError) as e:
+            log.warning(
+                "client_contributions[%r] is not JSON-serialisable, dropping: %s", pid, e
+            )
+            continue
+        if len(encoded) > _DIAG_MAX_CLIENT_PAYLOAD_BYTES:
+            log.warning(
+                "client_contributions[%r] exceeds %d bytes, dropping",
+                pid, _DIAG_MAX_CLIENT_PAYLOAD_BYTES,
+            )
+            continue
+        if total_bytes + len(encoded) > _DIAG_MAX_CONTRIBUTIONS_BYTES:
+            log.warning(
+                "client_contributions aggregate size limit (%d bytes) reached, "
+                "dropping remaining entries",
+                _DIAG_MAX_CONTRIBUTIONS_BYTES,
+            )
+            break
+        result[pid] = contribution
+        total_bytes += len(encoded)
+    return result or None
+
+
+@router.post("/api/diagnostics/export")
+def export_diagnostics(payload: dict = Body(default_factory=dict)):
+    """Build a diagnostic bundle and stream it back as a zip download.
+
+    The browser layers in `client_console`, `client_hardware`,
+    `client_ua`, and `local_storage` before posting; the server adds
+    server logs, hardware, plugin inventory, and packages everything
+    into a single zip.
+
+    Errors during plugin diagnostics callables are caught and logged
+    to the bundle's manifest `notes` rather than failing the export.
+    """
+    from plugins import LOADED_PLUGINS, PLUGINS_LOCK
+
+    redact = _diag_coerce_bool(payload.get("redact", True), default=True)
+    include = _diag_normalize_include(payload.get("include"))
+    client_console = _diag_cap_console(payload.get("client_console"))
+    client_hardware = _diag_cap_dict(payload.get("client_hardware"))
+    client_ua = _diag_cap_dict(payload.get("client_ua"))
+    local_storage = _diag_cap_dict(payload.get("local_storage"))
+    # Fetch the plugin list first so we can filter contributions to known
+    # plugin ids before serialising — prevents a crafted request from
+    # forcing large allocations for plugins build_bundle() would drop.
+    with PLUGINS_LOCK:
+        plugins_snapshot = list(LOADED_PLUGINS)
+    known_ids = {p.get("id") for p in plugins_snapshot if isinstance(p.get("id"), str)}
+    client_contributions = _diag_cap_contributions(
+        payload.get("client_contributions"), known_ids=known_ids
+    )
+
+    zip_bytes, filename, _manifest = _diag_build(
+        feedBack_version=appstate.running_version(),
+        config_dir=appstate.config_dir,
+        dlc_dir=_get_dlc_dir(),
+        log_file=_diag_log_file(),
+        loaded_plugins=plugins_snapshot,
+        include=include,
+        redact=redact,
+        client_console=client_console,
+        client_hardware=client_hardware,
+        client_ua=client_ua,
+        local_storage=local_storage,
+        client_contributions=client_contributions,
+        log=log,
+        plugins_root=_diag_plugins_roots(),
+    )
+    return Response(
+        content=zip_bytes,
+        media_type="application/zip",
+        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
+    )
+
+
+@router.get("/api/diagnostics/preview")
+def preview_diagnostics(
+    redact: bool = True,
+    system: bool = True,
+    hardware: bool = True,
+    logs: bool = True,
+    console: bool = True,
+    plugins: bool = True,
+):
+    """Return what `/api/diagnostics/export` would produce, minus the
+    actual file contents — file tree, sizes, schemas, redaction counts.
+    Lets the Settings UI show the user what's about to be sent."""
+    from plugins import LOADED_PLUGINS, PLUGINS_LOCK
+
+    include = {
+        "system": system,
+        "hardware": hardware,
+        "logs": logs,
+        "console": console,
+        "plugins": plugins,
+    }
+    with PLUGINS_LOCK:
+        plugins_snapshot = list(LOADED_PLUGINS)
+    return _diag_preview(
+        feedBack_version=appstate.running_version(),
+        config_dir=appstate.config_dir,
+        dlc_dir=_get_dlc_dir(),
+        log_file=_diag_log_file(),
+        loaded_plugins=plugins_snapshot,
+        include=include,
+        redact=redact,
+        log=log,
+        plugins_root=_diag_plugins_roots(),
+    )
+
+
+@router.get("/api/diagnostics/hardware")
+def diagnostics_hardware():
+    """Backend hardware probe (cross-platform). Reusable independently
+    of the bundle export — handy for "what's my GPU" plugin queries."""
+    return _diag_hardware()

server.py

@@ -55,7 +55,7 @@ from dlc_paths import _get_dlc_dir, _resolve_dlc_path
 # Lives in lib/ because that is the one core dir every packaging path copies.
 import appstate
 # Extracted route modules. They import `appstate`, never `server` — one-way graph.
-from routers import audio_effects, artist_aliases, loops, playlists, ws_highway, chart, wanted, library_extras, shop, progression, profile, stats, version
+from routers import audio_effects, artist_aliases, loops, playlists, ws_highway, chart, wanted, library_extras, shop, progression, profile, stats, version, diagnostics
 import sloppak as sloppak_mod
 import loosefolder as loosefolder_mod
 # Pure text-matching engine for MusicBrainz enrichment (P8): denoise/score/
@@ -5257,6 +5257,11 @@ def _running_version() -> str:
     return "unknown"
 
 
+# _running_version is defined below the import-top configure() calls, so publish
+# it here (configure is idempotent/additive) for routers/diagnostics.py.
+appstate.configure(running_version=_running_version)
+
+
 def _validate_server_config_types(cfg: dict) -> str | None:
     """Type-and-range gate for the server_config block of an import
     bundle, mirroring the per-key checks in `POST /api/settings`. The
@@ -5983,277 +5988,16 @@ def import_settings(bundle: dict):
     }
 
 
-# ── Diagnostic bundle export (feedBack#166) ──────────────────────────
+# ── Diagnostic bundle export (feedBack#166) → routers/diagnostics.py (R3) ────
-#
+# The pure caps/normalisers are re-exported so existing server._diag_* /
-# One-click "Export Diagnostics" in Settings produces a redacted zip
+# server._DIAG_* tests keep resolving (none of them monkeypatch these).
-# combining server logs, system info, hardware (CPU/GPU/RAM), plugin
+from routers.diagnostics import (  # noqa: E402  (re-export for test compatibility)
-# inventory, and the browser-side console transcript + hardware probe.
+    _diag_cap_console, _diag_cap_contributions, _diag_cap_dict,
-# The bundle format is specified in docs/diagnostics-bundle-spec.md.
+    _diag_coerce_bool, _diag_normalize_include,
-
+    _DIAG_MAX_CLIENT_PAYLOAD_BYTES, _DIAG_MAX_CONSOLE_BYTES,
-from fastapi import Body
+    _DIAG_MAX_CONSOLE_ENTRIES, _DIAG_MAX_CONTRIBUTIONS_BYTES,
-
+)
-from diagnostics_bundle import build_bundle as _diag_build, preview_bundle as _diag_preview
+app.include_router(diagnostics.router)
-from diagnostics_hardware import collect as _diag_hardware
-
-
-def _diag_log_file() -> Path | None:
-    raw = os.environ.get("LOG_FILE", "").strip()
-    if not raw:
-        return None
-    return Path(raw)
-
-
-def _diag_plugins_roots() -> list[Path]:
-    """Return all plugin root directories for orphan scanning.
-
-    Includes both the built-in ``plugins/`` directory and
-    ``FEEDBACK_PLUGINS_DIR`` when set, so user-installed plugins and
-    orphans in the external dir are reflected in the bundle.
-    """
-    roots: list[Path] = []
-    user_dir = getenv_compat("FEEDBACK_PLUGINS_DIR", "").strip()
-    if user_dir:
-        p = Path(user_dir)
-        if p.is_dir():
-            roots.append(p)
-    builtin = Path(__file__).parent / "plugins"
-    if builtin not in roots:
-        roots.append(builtin)
-    return roots
-
-
-def _diag_coerce_bool(v, *, default: bool = True) -> bool:
-    """Coerce a request-side value to bool, accepting both JSON booleans and
-    string representations.
-
-    - Falsy strings: ``"false"``, ``"0"``, ``"no"``, ``""`` → ``False``
-    - ``None`` → *default*
-    - Everything else (including ``"true"``, ``"1"``) → ``True``
-    """
-    if v is None:
-        return default
-    if isinstance(v, bool):
-        return v
-    if isinstance(v, str):
-        return v.strip().lower() not in ("false", "0", "no", "")
-    return bool(v)
-
-
-def _diag_normalize_include(include: dict | None) -> dict:
-    """Coerce request-side flags to the booleans build_bundle expects.
-    Missing keys default to True so a bare {} request still produces
-    the full bundle.
-
-    Accepts both JSON booleans (``true``/``false``) and string
-    representations so callers that serialize flags as strings behave
-    consistently with the preview endpoint:
-    - Falsy strings: ``"false"``, ``"0"``, ``"no"``, ``""`` → ``False``
-    - Everything else (including ``"true"``, ``"1"``, ``"yes"``) → ``True``
-    """
-    keys = ("system", "hardware", "logs", "console", "plugins")
-    if not isinstance(include, dict):
-        return {k: True for k in keys}
-
-    return {k: _diag_coerce_bool(include.get(k), default=True) for k in keys}
-
-
-# Server-side caps on client-supplied payload sections.  diagnostics.js
-# enforces a 500-entry / ~250 KB ring buffer on the browser side; these
-# bounds give generous headroom while still preventing a crafted POST from
-# forcing the server to allocate arbitrarily large in-memory bundles.
-_DIAG_MAX_CONSOLE_ENTRIES = 1000          # hard cap: truncate silently
-_DIAG_MAX_CONSOLE_BYTES = 2 * 1024 * 1024  # 2 MB hard cap on total console list
-_DIAG_MAX_CLIENT_PAYLOAD_BYTES = 2 * 1024 * 1024   # 2 MB per dict section
-_DIAG_MAX_CONTRIBUTIONS_BYTES = 4 * 1024 * 1024    # 4 MB aggregate cap for contributions
-
-
-def _diag_cap_console(v) -> list | None:
-    """Return *v* if it is a list, truncated to _DIAG_MAX_CONSOLE_ENTRIES entries
-    and _DIAG_MAX_CONSOLE_BYTES total.  Entries are accumulated until either cap
-    is reached; no partial-entry splitting occurs."""
-    if not isinstance(v, list):
-        return None
-    result = v[:_DIAG_MAX_CONSOLE_ENTRIES]
-    # Also enforce a byte cap — the count cap alone does not bound memory when
-    # entries contain arbitrarily large strings.
-    try:
-        out = []
-        total = 0
-        for entry in result:
-            encoded = json.dumps(entry, separators=(",", ":")).encode("utf-8", errors="replace")
-            if total + len(encoded) > _DIAG_MAX_CONSOLE_BYTES:
-                break
-            out.append(entry)
-            total += len(encoded)
-        return out
-    except (TypeError, ValueError):
-        return None
-
-
-def _diag_cap_dict(v) -> dict | None:
-    """Return *v* if it is a dict whose JSON serialisation fits within
-    _DIAG_MAX_CLIENT_PAYLOAD_BYTES, otherwise return None."""
-    if not isinstance(v, dict):
-        return None
-    try:
-        encoded = json.dumps(v, separators=(",", ":")).encode("utf-8", errors="replace")
-    except (TypeError, ValueError) as e:
-        log.warning("diagnostics client payload is not JSON-serialisable, dropping: %s", e)
-        return None
-    if len(encoded) > _DIAG_MAX_CLIENT_PAYLOAD_BYTES:
-        return None
-    return v
-
-
-def _diag_cap_contributions(v, known_ids=None) -> dict | None:
-    """Apply per-plugin and aggregate size caps on client_contributions.
-
-    Unlike _diag_cap_dict(), which drops the whole dict when any plugin
-    exceeds the limit, this function caps each plugin independently so
-    one noisy plugin does not silence every other plugin's contribution.
-
-    Parameters
-    ----------
-    v:
-        The raw contributions dict from the POST payload.
-    known_ids:
-        When provided, contributions from plugins not in this set are
-        skipped *before* serialisation, preventing a malicious caller
-        from forcing the server to JSON-encode hundreds of near-limit
-        payloads that ``build_bundle()`` would later discard anyway.
-        ``None`` means "accept all plugin ids" (used in tests / preview).
-    """
-    if not isinstance(v, dict):
-        return None
-    result = {}
-    total_bytes = 0
-    for pid, contribution in v.items():
-        if not isinstance(pid, str):
-            continue
-        # Filter unknown plugin ids early — before serialising — so a
-        # crafted request cannot force large allocations for plugins that
-        # build_bundle() would drop.
-        if known_ids is not None and pid not in known_ids:
-            continue
-        try:
-            encoded = json.dumps(contribution, separators=(",", ":")).encode("utf-8", errors="replace")
-        except (TypeError, ValueError) as e:
-            log.warning(
-                "client_contributions[%r] is not JSON-serialisable, dropping: %s", pid, e
-            )
-            continue
-        if len(encoded) > _DIAG_MAX_CLIENT_PAYLOAD_BYTES:
-            log.warning(
-                "client_contributions[%r] exceeds %d bytes, dropping",
-                pid, _DIAG_MAX_CLIENT_PAYLOAD_BYTES,
-            )
-            continue
-        if total_bytes + len(encoded) > _DIAG_MAX_CONTRIBUTIONS_BYTES:
-            log.warning(
-                "client_contributions aggregate size limit (%d bytes) reached, "
-                "dropping remaining entries",
-                _DIAG_MAX_CONTRIBUTIONS_BYTES,
-            )
-            break
-        result[pid] = contribution
-        total_bytes += len(encoded)
-    return result or None
-
-
-@app.post("/api/diagnostics/export")
-def export_diagnostics(payload: dict = Body(default_factory=dict)):
-    """Build a diagnostic bundle and stream it back as a zip download.
-
-    The browser layers in `client_console`, `client_hardware`,
-    `client_ua`, and `local_storage` before posting; the server adds
-    server logs, hardware, plugin inventory, and packages everything
-    into a single zip.
-
-    Errors during plugin diagnostics callables are caught and logged
-    to the bundle's manifest `notes` rather than failing the export.
-    """
-    from plugins import LOADED_PLUGINS, PLUGINS_LOCK
-
-    redact = _diag_coerce_bool(payload.get("redact", True), default=True)
-    include = _diag_normalize_include(payload.get("include"))
-    client_console = _diag_cap_console(payload.get("client_console"))
-    client_hardware = _diag_cap_dict(payload.get("client_hardware"))
-    client_ua = _diag_cap_dict(payload.get("client_ua"))
-    local_storage = _diag_cap_dict(payload.get("local_storage"))
-    # Fetch the plugin list first so we can filter contributions to known
-    # plugin ids before serialising — prevents a crafted request from
-    # forcing large allocations for plugins build_bundle() would drop.
-    with PLUGINS_LOCK:
-        plugins_snapshot = list(LOADED_PLUGINS)
-    known_ids = {p.get("id") for p in plugins_snapshot if isinstance(p.get("id"), str)}
-    client_contributions = _diag_cap_contributions(
-        payload.get("client_contributions"), known_ids=known_ids
-    )
-
-    zip_bytes, filename, _manifest = _diag_build(
-        feedBack_version=_running_version(),
-        config_dir=CONFIG_DIR,
-        dlc_dir=_get_dlc_dir(),
-        log_file=_diag_log_file(),
-        loaded_plugins=plugins_snapshot,
-        include=include,
-        redact=redact,
-        client_console=client_console,
-        client_hardware=client_hardware,
-        client_ua=client_ua,
-        local_storage=local_storage,
-        client_contributions=client_contributions,
-        log=log,
-        plugins_root=_diag_plugins_roots(),
-    )
-    return Response(
-        content=zip_bytes,
-        media_type="application/zip",
-        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
-    )
-
-
-@app.get("/api/diagnostics/preview")
-def preview_diagnostics(
-    redact: bool = True,
-    system: bool = True,
-    hardware: bool = True,
-    logs: bool = True,
-    console: bool = True,
-    plugins: bool = True,
-):
-    """Return what `/api/diagnostics/export` would produce, minus the
-    actual file contents — file tree, sizes, schemas, redaction counts.
-    Lets the Settings UI show the user what's about to be sent."""
-    from plugins import LOADED_PLUGINS, PLUGINS_LOCK
-
-    include = {
-        "system": system,
-        "hardware": hardware,
-        "logs": logs,
-        "console": console,
-        "plugins": plugins,
-    }
-    with PLUGINS_LOCK:
-        plugins_snapshot = list(LOADED_PLUGINS)
-    return _diag_preview(
-        feedBack_version=_running_version(),
-        config_dir=CONFIG_DIR,
-        dlc_dir=_get_dlc_dir(),
-        log_file=_diag_log_file(),
-        loaded_plugins=plugins_snapshot,
-        include=include,
-        redact=redact,
-        log=log,
-        plugins_root=_diag_plugins_roots(),
-    )
-
-
-@app.get("/api/diagnostics/hardware")
-def diagnostics_hardware():
-    """Backend hardware probe (cross-platform). Reusable independently
-    of the bundle export — handy for "what's my GPU" plugin queries."""
-    return _diag_hardware()
 
 
 # ── Plugin-provided routes are registered at startup via plugins/__init__.py ─