docs: record Phase 6 failure-gate checkpoint

docs/screenshare-audio-exclusion-impl-plan.md

@@ -14,7 +14,9 @@ locally in PixelPass (`98cde2c`): the hidden production path creates, retains, r
 crash-cleans exact-channel non-lingering fan-out links. The four versioned Phase 6 status events
 are built, validated and committed locally in PixelPass (`5a65f50`). Capture-sink replacement
 and successful exact-channel relinking are built, validated and committed locally in PixelPass
-(`d09ee9b`). The remaining Phase 6 matrix rows, plus phases 7–9, are not built — nothing
+(`d09ee9b`). **The Row 1 mutation-edge identity gate and the Row 8d/8e fail-closed
+construction gates are built, validated and committed locally in PixelPass (`6be07ef`).**
+The remaining Phase 6 refusal/matrix rows, plus phases 7–9, are not built — nothing
 released to date changes the feature's user-visible behaviour. **Phase 6 remains the current
 front.**
 **Date:** 2026-07-21 (v4); status line refreshed 2026-08-21
@@ -718,7 +720,23 @@ ancestry becoming unsafe.
 >
 > This does **not** complete Phase 6. The remaining failure-matrix rows are still open. The public
 > mode selector remains Phase 7 and PeerSpeak parsing/UI integration remains Phase 8. The last
-> committed PixelPass checkpoint is `d09ee9b`.
+> committed PixelPass checkpoint is `6be07ef`.
+>
+> **Row 1 plus Row 8d/8e slice — built, validated and committed locally as `6be07ef` on
+> 2026-08-21.** The production
+> link mutator now applies serial revalidation to retained proxies as well as new requests; a
+> node/global-id recycle between planning and mutation yields zero `create_link` calls and drops
+> any stale retained intent. `CapturePlan` has one injectable production construction seam, and
+> separate optimized-release gates prove both capture-sink construction failure and the
+> observer's sticky readiness timeout escape `DesktopExcluding` as errors without ever resolving
+> the default monitor or constructing legacy `Routing`.
+>
+> The full suite passes with 335 passed, 0 failed and 12 ignored. All three new gates pass in an
+> optimized release build; strict all-target Clippy, formatting and `git diff --check` pass. All
+> three serialized Phase 6 live audio-plan gates still pass, `pixelpass --doctor` passes, and the
+> final Pulse/PipeWire/process residue scan is empty. Nix remains unavailable, so validation used
+> system Rust 1.97.1. The disposable 1.0 GiB release cache was removed afterward, leaving 12 GiB
+> free. Next is the independent Row 6a/6b/6c refusal/reason slice; Phase 6 is not complete.
 
 Failure ⇒ report the stream unsupported. **Never** fall back to the default monitor — and after
 0d that fallback is unconstructible in this mode, by either path.

docs/screenshare-audio-exclusion-plan.md

@@ -8,7 +8,9 @@ channel-planning prerequisite is committed locally in PixelPass `781defc`; the f
 live fan-out mutation slice is built, validated and committed locally in PixelPass `98cde2c`.
 The four versioned causal status events are built, validated and committed locally in PixelPass
 `5a65f50`. Capture-sink replacement and successful all-channel relinking are built, validated
-and committed locally in PixelPass `d09ee9b`.
+and committed locally in PixelPass `d09ee9b`. The Row 1 mutation-edge identity gate and Row
+8d/8e fail-closed construction gates are built, validated and committed locally in PixelPass
+`6be07ef`.
 **Date:** 2026-08-21 (v1: 07-19 · v2: 07-20 · Option C 07-20 · v3.1 r4 · v3.2 r5 · v3.3 r6 ·
 v3.4 r7 · v3.5 r8 · v3.6 r9 · v3.7 r10 · v3.8 r11 2026-08-21)
 **Origin:** Joe's suggestion — "whitelist all audio except audio coming from peerspeak."
@@ -1393,8 +1395,16 @@ host-path sink-destruction/relink gate pass; the full suite reports 332 passed a
 three serialized Phase 6 live gates pass together, and strict Clippy plus `pixelpass --doctor`
 remain clean.
 
-1. **Continue Phase 6:** complete the remaining failure-matrix rows; sink replacement/relink
-   recovery now passes through the real host path and is committed locally in `d09ee9b`.
+PixelPass commit `6be07ef` closes Row 1 and Row 8d/8e. Mutation-edge serial
+revalidation now covers retained proxies as well as new links, and a recycled identity produces
+zero unsafe creates. Two optimized-release fault-injection gates prove capture-sink construction
+failure and readiness timeout both fail `DesktopExcluding` closed without resolving the legacy
+default monitor or constructing legacy routing. Full validation reports 335 passed and 12
+ignored; strict Clippy, all three serialized live Phase 6 gates, diagnostics and residue checks
+pass. The next bounded slice is the three independent Row 6a/6b/6c refusal/reason fixtures.
+
+1. **Continue Phase 6:** add independent refusal/reason fixtures for Row 6a `port.exclusive`,
+   Row 6b encoded streams and Row 6c IEC958 passthrough.
 2. Carry the revised row-9 partition forward: music-only and a different-device microphone
    stay eligible; same-device capture and a tainted-monitor capture are excluded.
 3. Preserve the new live mutation slice's ownership, serial-revalidation, fail-closed,