docs: launch-options reference + the test that keeps it honest

The client reads 161 ACDREAM_* environment variables across 79 files. Only
about 25 were written down, and the audit found the documentation drifting
in both directions: CLAUDE.md still advertised ACDREAM_RUN_SKILL /
ACDREAM_JUMP_SKILL (deleted; skills are server-authoritative now, and the
jump fallback is 300, not the documented 200), while flags with real
side effects had no description at all.

docs/launch-options.md documents every one by lifecycle — production,
command line, measurement, automation, permanent diagnostics, temporary
probes, deprecated, retired — with a mandatory side-effects column. That
column is the point: #432 cost three days of taxed measurements because
ACDREAM_AUTOMATION_ARTIFACT_DIR reads like an output path and also builds
a per-frame diagnostics referee, and ACDREAM_STREAM_RADIUS silently
measures a streaming window production never uses. Rows now say so. Other
surprises the audit surfaced and recorded: ACDREAM_DUMP_SCENERY_Z swaps in
a duplicate scenery-placement path rather than only logging,
ACDREAM_PROBE_VIS silently also enables ACDREAM_PROBE_ENVCELL, and
ACDREAM_DUMP_ENTITY's id list doubles as an unrelated probe's watchlist.

LaunchOptionsDocumentationTests enforces it, because a hand-maintained list
of 161 flags is stale within a week: an undocumented flag fails, and so
does a documented row whose read site was deleted. It scans string literals
rather than GetEnvironmentVariable call shapes — the startup path reads
through an injected delegate, so a call-shaped pattern silently missed
ACDREAM_LIVE, ACDREAM_PAK_PATH and every other production flag. A third
test freezes per-file direct-read debt by exact count (20 files outside the
owner classes), so structure rules 4 and 5 can be paid down but not
regressed.

CLAUDE.md's 94-line env-var section becomes a 16-line pointer, and its
stale test-character paragraph is corrected.

Also fixed, all doc-vs-code mismatches the audit proved:
- RenderingDiagnostics.FrameProfEnabled described a GPU-query self-disable
  that Campaign V slice V11 deleted.
- Two comments named ACDREAM_RENDER_BACKEND as a live co-requisite; it died
  with the OpenGL backend.
- EnvCellRenderer.CollectCellAuditLines and its ACDREAM_A8_AUDIT doc: the
  method had no caller anywhere and its documented caller never existed.

Filed rather than fixed, to keep this a documentation change: #434 (the
DebugPanel/DebugVM surface is never constructed, so ~40 "runtime-toggleable"
comments are false and 35 env reads are unreachable) and #435 (17 temporary
probes outlived their closed investigations; 14 more name no owner).

Full hermetic suite 12,202 passed / 0 failed.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AcDream.Core/Rendering/RenderingDiagnostics.cs

@@ -764,10 +764,12 @@ public static class RenderingDiagnostics
     /// (swap-to-swap), whole-frame GPU time, per-stage CPU attribution,
     /// per-frame allocation counters, reported as one <c>[frame-prof]</c>
     /// line every ~5 s. Permanent apparatus (every MP-track gate reads it) —
-    /// do NOT strip with session probes. The whole-frame GPU query is
-    /// self-disabled while <c>ACDREAM_WB_DIAG=1</c> (GL forbids nested
-    /// TimeElapsed queries; WbDrawDispatcher owns per-pass queries under
-    /// that flag — the 2026-06-23 "separate flags" measurement lesson).
+    /// do NOT strip with session probes. This paragraph previously claimed
+    /// the whole-frame GPU query self-disables under <c>ACDREAM_WB_DIAG=1</c>;
+    /// Campaign V slice V11 deleted that self-disable along with the GL query
+    /// ring it protected, and the two flags are now independent — see
+    /// <c>FrameProfiler</c>'s own class doc. Every backend reports GPU time
+    /// through <c>FrameProfiler.RecordGpuSample</c>.
     /// Initial state from <c>ACDREAM_FRAME_PROF=1</c>; runtime-toggleable
     /// via the DebugPanel mirror (<c>DebugVM.FrameProf</c>).
     /// Spec: docs/superpowers/specs/2026-07-05-modern-pipeline-design.md §5.