fix(tuner): remove unused settings + fix sidebar panel position (#661)

Removes the Floating Button and Tuning Visibility settings sections and finishes retiring their still-live config: drops the disabledTunings menu filter and showFloatingButton gate from screen.js/ui.js and their persistence in routes.py (retired keys are stripped on write). Repositions the tuner panel opened from the v3 sidebar Plugins popover to anchor beside it via the host's stable plugin-control slot API (falling back to the popover id), clamped to the viewport so it can't open off-screen, and re-anchored on resize. Updates tuner config tests to the retired-key behavior; plugins/tuner 1.3.2 -> 1.3.3.

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

CHANGELOG.md

@@ -10,6 +10,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - **Player frame-time hotspots removed (trace-backed) + weak-hardware hardening.** A Chrome performance trace of a 3D-highway session surfaced two core per-frame layout-thrash sources, now fixed: the highway's visibility check read `canvas.offsetParent` every rAF frame (forces style/layout recalc — now sampled every 10th frame with a cached value, force-refreshed on init/canvas-replace/resize/override-clear), and the v3 player chrome loop called `matches(':hover')` per frame and unconditionally rewrote the Up-Next pill's `textContent`/bar width at 6 Hz (now hover-tracked via mouseenter/mouseleave, DOM writes only on value change, progress bar moved from `width` to compositor-only `scaleX`). The 3D highway pre-warms shader programs (`ren.compile`) and deterministic label textures at init — and chart-dependent chord/section label textures on first draw — so first-appearance shader-compile/texture-upload frame spikes move into the load spinner. For weaker hardware: the per-frame renderer bundle is now a single reused object instead of a fresh ~35-field allocation per frame (object identity is stable and meaningless; array fields still swap reference on chart changes), custom viz get `bundle.lowerBoundT`/`bundle.lowerBoundTime` binary-search helpers for visible-window culling, the default 2D highway's beat lines no longer scan every beat in the song per frame, and the 3D highway stops reading `localStorage` per frame (1 Hz poll) and caches its lyrics text-measurement layout per displayed line instead of re-measuring every syllable every frame. A second, throttled-CPU trace pass additionally removed: shader-program re-resolution churn from label texture swaps (`material.needsUpdate` is now only set on a null↔texture transition — swapping between two cached label textures never changes the compiled program), the 3D highway's per-frame `getBoundingClientRect` layout read in its canvas-size self-check (now every 10th frame, still immediate on backing-store change), and the core 60 Hz HUD clock rewriting `textContent` on every tick (now write-on-change, ~1/s). The dominant residual — steady `getParameters` shader-program re-resolution (~4% of throttled main thread) — turned out to be Three r158+'s transparent-DoubleSide two-pass rendering, which sets `material.needsUpdate` twice per object per frame; all 18 of the 3D highway's transparent DoubleSide materials are flat unlit quads (labels, rails, chord frames, lanes), so they now declare `forceSinglePass: true`, eliminating the recompile churn and halving those objects' draw calls.
 
+### Fixed
+- **Tuner: finished the "remove unused settings" cleanup and fixed the sidebar panel position.** The Floating Button and Tuning Visibility settings sections were removed, but their config was still live: `disabledTunings` still filtered the tuner menu (with no UI left to re-enable a hidden tuning — a one-way trap) and `showFloatingButton` still gated the floating launcher. Both are now fully retired — the enforcement paths in `plugins/tuner/screen.js`/`utils/ui.js` and the persistence in `plugins/tuner/routes.py` are gone (and `routes.py` strips the retired keys on write, so stale values are purged). The tuner panel opened from the v3 sidebar Plugins rail popover now anchors beside it via the host's stable plugin-control slot API (falling back to the popover id), is **clamped to the viewport** so it can't open off the right/bottom edge on narrow/short windows, and re-anchors on window resize. `plugins/tuner` → 1.3.3.
+
 ### Added
 - **3D Keys Highway: audio-reactive background ambience + score effects (parity slice 4 — completes the keys side of the visual-parity epic).** The gradient sky behind the highway gains the guitar's **background ambience styles** — drifting **Particles**, pitch-class-colored pulsing **Stage lights**, wireframe **Geometric** shapes, or Off — driven by the shared audio-analyser bridge (stems-first on sloppaks, one-shot `#audio` fallback; bass/mid/treble bands, 5 ms cache) with an **Ambience intensity** slider and an **Audio-reactive** toggle. And the score talks back: a **score-FX overlay** canvas draws rising **“+1” pops** off each scored key, an **expanding ring every 10-combo tier**, **milestone bursts** at 25/50/100 streak, and a brief **red flicker** when a 3+ streak breaks (wrong notes and swept misses both count). All settings-gated and on by default (`keys3d_bg_*`), pooled, cleared when idle, torn down with the scene. Butterchurn/image/video remain out of scope. The `#audio` analyser tap is also **shared across visualizers** now (`window.__feedBackAudioTap` — whoever taps first publishes, everyone else adopts, `highway_3d` included), so switching between or splitting the guitar/drum/keys highways can't strand a permanently non-reactive backdrop, and the tap is never created before the page has user activation (a suspended AudioContext would silence live playback). Tests: bg-style id validation + FX defaults (30 total).
 - **3D Keys Highway: the anti-plastic pass — lacquered note gems, glossy piano-black keys, a studio environment, scene themes and a gradient sky (parity slice 3).** The note gems move to `MeshPhysicalMaterial` with a full **clearcoat** (roughness 0.32, clearcoat 1.0/0.18, envMapIntensity 0.9): a sharp lacquer highlight over the colored body instead of the old dead matte surface — glass, not plastic. What sells it is **image-based lighting**: the same procedural PMREM "studio" environment as the drum highway (dark room + cool overhead / warm+cool side light strips, no addon dependency) feeds `scene.environment`, so the **black keys finally read as glossy piano black** (roughness 0.55 → 0.22, envMapIntensity 1.3) with visible strip reflections, whites keep an ivory sheen (0.42/0.55), and the highway floor gets a stage sheen (roughness 0.9 → 0.55, metalness 0.15). The flat background becomes a **vertical gradient** (lighter above the horizon → theme color → darker toward the keyboard), and the guitar highway's **11 scene themes** arrive (same names/values — your look carries across instruments; `default` preserves the original keys palette; pitch-class note/key colors are never themed — themes own the scene, Synthesia colors own the notes). Plus **Cinematic lighting** (ambient 0.55/key 1.3, on by default) and a **Glow strength** slider multiplying the note glow, key approach-glow and the sustain consume-flash (0.5 = stock). All live-applying from the Graphics settings (`keys3d_bg_theme` + `keys3d_bg_*`); the PMREM target and gradient texture are disposed with the scene. Tests: theme-table id parity + default-look preservation + fallbacks (28 total).