feat(achievements): wall sync drain worker + review fixes (epic PR3) (#592)

* feat(achievements): wall sync drain worker (epic PR3, client side)

Background dead-letter worker that POSTs queued Feat unlocks/removals to the
hosted feedback-achievements wall. Idle unless FEEDBACK_ACHIEVEMENTS_WALL_URL
is set; uses requests + the client-token header (mirrors lyrics_transcribe).

Dead-letter, never drop (pure engine.drain_decision):
  network err / 429 / 5xx -> keep pending (retry)
  other 4xx               -> dead_letter (diagnosable, replayable)
  2xx                     -> delete on server ack
remove-me enqueues a wall removal keyed by the reused player_hash.

Verified by an end-to-end staging round-trip (earn a Feat -> drains onto the
wall with name + short hash -> remove-me -> wall empties) with no IP in tables
or access logs. 42 plugin tests pass (test_sync.py adds the decision table +
ack/retry/dead-letter retention + four-field on-the-wire payload).

The hosted service lives in the new feedback-achievements repo.

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

* fix(achievements): address local review findings (epic)

Bugs caught in the pre-merge review loop:

- secret_witching Feat was DEAD: post_activity wrote witching_nights_run to the
  DB before snapshotting prev_tiers, so diff_unlocks never saw the fresh unlock.
  Fold the run into the activity delta instead (same asymmetry chart_encore
  uses) so the 7th-night unlock is detected. +regression tests.
- chart_encore broke across restarts: per-chart counter keyed on abs(hash(str)),
  which Python salts per-process (PYTHONHASHSEED). Use a stable sha1 digest so
  the same chart accumulates across sessions. +regression test.
- Bounded the per-activity counter read: _read_counters no longer pulls the
  unbounded chart_plays:* rows (they're bumped/read individually).
- screen.js: gate note:hit/miss on an active-song flag so tuner/calibration note
  events can't inflate Feats or flush a phantom chart:null session.
- screen.js: P-III — prefix the plugin localStorage key (achievements:profile-cat).
- screen.js: extract the duplicated local-ISO-date helper.

45 plugin tests pass (3 new). Wall-side review fixes are in the
feedback-achievements repo.

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

* feat(achievements): default the drain worker to the hosted wall

Point FEEDBACK_ACHIEVEMENTS_WALL_URL's default at the live got-feedback wall
(https://feedback-achievements.onrender.com) so the drain worker targets it out
of the box; still env-overridable for self-hosting/staging. Nothing publishes
unless the user opted in AND has a profile identity, so a default URL alone
sends nothing.

Tests disable the default (autouse fixture) so no test ever POSTs to production;
drain logic is covered via _drain_once() with an injected poster. 45 pass.

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

---------

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

tests/plugins/achievements/conftest.py

@@ -10,6 +10,17 @@ from fastapi.testclient import TestClient
 import routes as ach_routes
 
 
+@pytest.fixture(autouse=True)
+def _no_live_drain():
+    # routes now defaults the wall URL to the live onrender service, so setup()
+    # would auto-start the drain thread. Disable it for every test so no test
+    # ever POSTs to production; the drain logic is exercised via _drain_once()
+    # with an injected poster instead.
+    ach_routes._WALL_URL = ""
+    ach_routes._drain_started = False
+    yield
+
+
 @pytest.fixture
 def client(tmp_path):
     app = FastAPI()

tests/plugins/achievements/test_routes.py

@@ -54,6 +54,35 @@ def test_report_unlock_is_idempotent_and_tier_monotonic(client):
     assert higher["changed"] is True
 
 
+def test_witching_feat_unlocks_on_seventh_consecutive_night(client):
+    # Regression: the derived witching_nights_run counter must NOT be pre-written
+    # before the prev snapshot, or diff_unlocks never sees the fresh unlock.
+    unlocked_ever = []
+    for day in range(1, 8):
+        res = client.post("/api/plugins/achievements/activity",
+                          json={"night_session": True, "night_date": "2026-06-%02d" % day}).json()
+        unlocked_ever += [u["id"] for u in res["unlocked"]]
+    assert "secret_witching" in unlocked_ever, "witching feat never reported as unlocked"
+    feats = [f["id"] for f in client.get("/api/plugins/achievements/feats").json()["feats"]]
+    assert "secret_witching" in feats
+
+
+def test_witching_not_unlocked_before_seven(client):
+    for day in range(1, 7):  # only 6 nights
+        client.post("/api/plugins/achievements/activity",
+                    json={"night_session": True, "night_date": "2026-06-%02d" % day})
+    feats = [f["id"] for f in client.get("/api/plugins/achievements/feats").json()["feats"]]
+    assert "secret_witching" not in feats
+
+
+def test_chart_key_is_stable_not_builtin_hash(client):
+    import hashlib
+    import routes
+    # Deterministic across processes (sha1-based), unlike the salted builtin hash().
+    assert routes._chart_key("song.sloppak") == "chart_plays:" + hashlib.sha1(b"song.sloppak").hexdigest()[:16]
+    assert routes._chart_key("a") != routes._chart_key("b")
+
+
 def test_report_criterion_counts_distinct(client):
     url = "/api/plugins/achievements/report-criterion"
     assert client.post(url, json={"criterion_id": "x", "token": "a"}).json()["count"] == 1

tests/plugins/achievements/test_sync.py

@@ -0,0 +1,84 @@
+"""Wall-sync drain worker — dead-letter state machine (never drop)."""
+
+import json
+import sqlite3
+
+import pytest
+from fastapi import FastAPI
+from fastapi.testclient import TestClient
+
+import engine
+import routes as ach_routes
+
+
+# ── Pure decision table ──────────────────────────────────────────────────────
+
+@pytest.mark.parametrize("status,expected", [
+    (200, "ack"), (201, "ack"),
+    (None, "retry"),        # network error
+    (429, "retry"),         # backoff
+    (500, "retry"), (503, "retry"),  # transient server-side
+    (400, "dead"), (404, "dead"), (422, "dead"),  # client 4xx → dead-letter
+])
+def test_drain_decision(status, expected):
+    assert engine.drain_decision(status) == expected
+
+
+# ── Worker over a seeded queue ───────────────────────────────────────────────
+
+class _FakeMetaDB:
+    def get_profile(self):
+        return {"display_name": "Ada", "player_hash": "deadbeefcafe"}
+
+
+@pytest.fixture
+def opted_in_client(tmp_path):
+    (tmp_path / "config.json").write_text(json.dumps({"achievements_enabled": True}))
+    app = FastAPI()
+    ach_routes.setup(app, {"config_dir": str(tmp_path), "meta_db": _FakeMetaDB()})
+    c = TestClient(app)
+    c._tmp = tmp_path
+    return c
+
+
+def _queue(tmp_path):
+    db = sqlite3.connect(str(tmp_path / "achievements" / "achievements.db"))
+    try:
+        return [(i, k, s) for (i, k, s) in db.execute("SELECT id, kind, state FROM sync_queue")]
+    finally:
+        db.close()
+
+
+def test_ack_deletes_row(opted_in_client):
+    opted_in_client.post("/api/plugins/achievements/activity", json={"notes": 100000})
+    assert len(_queue(opted_in_client._tmp)) == 1
+    ach_routes._drain_once(post_fn=lambda kind, payload: 200)
+    assert _queue(opted_in_client._tmp) == []  # acked → gone
+
+
+def test_network_error_keeps_pending(opted_in_client):
+    opted_in_client.post("/api/plugins/achievements/activity", json={"notes": 100000})
+    ach_routes._drain_once(post_fn=lambda kind, payload: None)
+    rows = _queue(opted_in_client._tmp)
+    assert len(rows) == 1 and rows[0][2] == "pending"  # retained for retry
+
+
+def test_4xx_dead_letters_but_retains(opted_in_client):
+    opted_in_client.post("/api/plugins/achievements/activity", json={"notes": 100000})
+    ach_routes._drain_once(post_fn=lambda kind, payload: 400)
+    rows = _queue(opted_in_client._tmp)
+    assert len(rows) == 1 and rows[0][2] == "dead_letter"  # diagnosable, not dropped
+
+
+def test_drain_sends_exact_four_field_payload(opted_in_client):
+    opted_in_client.post("/api/plugins/achievements/activity", json={"notes": 100000})
+    captured = {}
+
+    def fake_post(kind, payload):
+        captured["kind"] = kind
+        captured["payload"] = payload
+        return 200
+
+    ach_routes._drain_once(post_fn=fake_post)
+    assert captured["kind"] == "unlock"
+    assert set(captured["payload"].keys()) == set(engine.WALL_PAYLOAD_KEYS)