fix #435 (part 1): delete 17 probes that outlived their closed investigations

Each of these was temporary apparatus added to chase one bug, and each was
supposed to be deleted in the commit that fixed it. Fourteen closed issues
later they were still here: #337's support/wire-mesh trio, #171's sticky
timeline, #119's viewer and entity dumps, #113's phantom probe, and a dozen
more. 3,493 lines removed; the client now reads 144 environment variables
instead of 161, and 47 temporary probes remain instead of 64.

This is not only tidying. Every probe leaves a branch on its hot path when
unset, several re-read the environment per call rather than caching, and
the volume buries the diagnostics that are actually load-bearing. It is
also a headless correctness matter: HeadlessStaticStateAudit reflects over
PhysicsDiagnostics' flags to refuse a multi-session host when any is set,
and cannot see probes that live outside that owner.

Four files went entirely — WalkMissDiagnostic.cs, CollisionMeshWireframe.cs
and two test files whose only subject was a deleted probe.
TransitionTypes.SetContactPlane also sheds its CallerMemberName /
CallerLineNumber parameters, which existed solely for #337's cpSrc=
attribution and carried the instruction to strip them with the probe
family; no call site passed them, so no behavior changes. F2's collision
overlay survives and reverts to its proxy-cylinder form, which is what
removing the ACDREAM_WIRE_MESH upgrade means.

LaunchOptionsDocumentationTests earned its keep here: it refused the
deletion until docs/launch-options.md moved the 17 rows into Retired and
the frozen direct-read counts came down (PhysicsEngine.cs to zero,
TransitionTypes.cs 3 to 2). The documentation could not drift during a
cleanup this wide.

The 14 probes that name no owning issue are deliberately NOT deleted.
Nothing records when they became safe to remove, and guessing is how a
future investigation loses apparatus it needed; #435 stays open for their
attribution.

Full hermetic suite 15,321 passed / 0 failed.

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

docs/ISSUES.md

@@ -24,9 +24,35 @@ What does NOT go here:
 - Every session: scan OPEN issues at start; promote/close anything we touched during the session before ending.
 - Promoting to a Phase: mark as `DONE (promoted to Phase X)` + commit SHA where the Phase entry landed.
 
-## #435 — Probe debt: 17 temporary probes outlived their closed investigations, 14 more name no owner
+## #435 — PARTLY CLOSED: Probe debt: 17 temporary probes outlived their closed investigations, 14 more name no owner
 
-**Status:** OPEN
+**Status:** The 17 orphaned probes are DELETED (2026-08-24) — 3,493 lines
+removed, flag count 161 → 144, temporary probes 64 → 47. Build clean; full
+hermetic suite 15,321 passed / 0 failed (baseline 15,333 minus the 12 tests
+whose only subject was a deleted probe). Four files went entirely:
+`WalkMissDiagnostic.cs`, `CollisionMeshWireframe.cs` and two probe-only test
+files. `LaunchOptionsDocumentationTests` did its job during the cleanup —
+it refused the deletion until the doc's rows moved to Retired and the frozen
+direct-read counts were lowered (`PhysicsEngine.cs` to zero,
+`TransitionTypes.cs` 3 → 2).
+
+Notable: `TransitionTypes.SetContactPlane` shed its `CallerMemberName` /
+`CallerLineNumber` parameters, which existed only for #337's `cpSrc=`
+attribution and were explicitly marked "strip with the probe family". No
+call site passed them, so no behavior changed. F2's collision overlay
+survives and reverts to the proxy-cylinder form, as intended when
+`ACDREAM_WIRE_MESH` went.
+
+**STILL OPEN — the 14 unattributed probes.** They name no owning issue, so
+nothing records when they are safe to remove. Deleting them on a guess is
+how a future investigation loses apparatus it needed. The right next step is
+attribution, not deletion: for each, find the commit that introduced it
+(`git log -S ACDREAM_PROBE_X`), record the issue in its
+`docs/launch-options.md` row, and only then decide. Deliberately deferred.
+
+**Original report follows.**
+
+**Status (original):** OPEN
 **Severity:** LOW (no runtime defect; hot-path clutter and measurement noise)
 **Filed:** 2026-08-24 (measured during the launch-options audit)
 **Component:** diagnostics ownership