docs(rfc): revise the batch for the hooks-stack base; add three post-stack RFCs

The branch now bases on the hooks stack (PR #138's head), so every
'in-flight' reference to stack content became a current-state fact.
Audited all nine RFCs + three supplements claim-by-claim against the
merged tree (none invalidated; several strengthened):

- prune-dead-core-spine-surface: describe the landed tools/pre-execute →
  dispatch → tools/post-execute pipeline — listeners return Decisions,
  the registry builds every result and snapshots it to protect callId,
  and a second (mutation-guard) test pins the field; drop the resolved
  wait-for-interception hedge; scope the additionalContext ferry out.
- prune-producerless-vocabulary-variants: the ui-stdio fixture migrated
  off the continuation trigger (llm-replay is the sole writer now); the
  stack's own additions (rejected, prompt/blocked, hook/invoked+result)
  all arrived with producers — the admission policy demonstrated live.
- prune-unimplemented-subagent-vocabulary: enrichment landed as
  lastAssistantMessage only (agentType was dropped in the stack's own
  review — the same judgment this RFC extends); the seam RFC now names
  tools/pre-execute deny, which exists, sharpening the re-add path.
- drop-inert-request-knobs / drop-image-content-block /
  trim-acp-bridge-unreachable-surface: current-state rewordings (shipped
  bridges set no request fields; only compact-basic has explicit image
  arms; 13 hook goldens also pin agentInfo).
- generic-long-running-tool-runtime census: second production seam
  consumer (hook-protocol runHook: resolve+run, stdin/env, foreground
  only — background machinery stays single-consumer); scrub-duplication
  blast radius.
- discover-package-inventory: identical 54-entry tsconfig reference
  sets; the comparesLog scenario knob (fixture-derivable, like recorded).
- unify-agent-and-session-id: third divergence site (in-process subagent
  children mint two UUIDs), the hooks bridge id-lookups, and ui-stdio's
  labelBySession map as a consumer that deletes under unification.

New RFCs from the post-stack survey:
- remove-agent-steering-mirror: the last mirror-of-durable event; zero
  production listeners; both retention RFCs deferred its fate, and the
  'no durable twin' rationale is contradicted by the adjacent append.
- tighten-hook-protocol-contract: producer-less 'native' dialect,
  parsed-and-discarded suppressOutput, and hook/result semantics
  (truncation + decision-string) defined twice in the bridges instead
  of the lib that owns the event.
- single-source-acp-replay-config: cordis.yml/cordis.snapshot.yml differ
  by exactly one plugin entry, with no gate on the forced symmetry.

docs/rfc/proposed/architecture/2026-06-20-generic-long-running-tool-runtime.md

@@ -24,7 +24,7 @@ The runtime should own:
 
 ## Current seam consumption
 
-A consumer census of the surface the runtime would carve up. Production (`packages/bash/tool-bash/src/index.ts`) consumes `resolve`, `run`, `start`, `ownerOf`, `readOutput`, `kill`, and `onTaskDone`. `get()`/`list()` have test-harness consumers only — they were removed once and reverted on the merits (the implementation note in [prune dead methods from the persistence seam](../../implemented/simplification/2026-06-20-prune-dead-seam-methods.md) records the test-migration cost dwarfing the surface removed). The per-task `BashTask.done` promise has no consumer through the public seam either (`dsh-tool-bash` completes via `onTaskDone`), but it is production-load-bearing INSIDE the implementation: `dsh-bash-local`'s disposal awaits it to reach quiescence. The seam therefore exposes two public completion representations — the per-task promise and the global `onTaskDone` listener registry — and the shipped consumer uses only the latter: the runtime should pick exactly one public completion surface and record which. One shape wart for the split to dissolve: `BashExecSpec.timeoutMs` is required but ignored by `start()`, an artifact of sharing one spec type between foreground and background execution.
+A consumer census of the surface the runtime would carve up. Production has two seam consumers: `packages/bash/tool-bash/src/index.ts` consumes `resolve`, `run`, `start`, `ownerOf`, `readOutput`, `kill`, and `onTaskDone`; and the hook bridges — via `dsh-hook-protocol`'s `runHook` (`packages/hooks/hook-protocol/src/runner.ts`) — consume `resolve` + `run` only, a foreground-only trusted-plugin caller that sets the seam's `stdin`/`env` fields, so the background machinery stays single-consumer (which sharpens the extraction premise). `get()`/`list()` have test-harness consumers only — they were removed once and reverted on the merits (the implementation note in [prune dead methods from the persistence seam](../../implemented/simplification/2026-06-20-prune-dead-seam-methods.md) records the test-migration cost dwarfing the surface removed). The per-task `BashTask.done` promise has no consumer through the public seam either (`dsh-tool-bash` completes via `onTaskDone`), but it is production-load-bearing INSIDE the implementation: `dsh-bash-local`'s disposal awaits it to reach quiescence. The seam therefore exposes two public completion representations — the per-task promise and the global `onTaskDone` listener registry — and the shipped consumers use only the latter: the runtime should pick exactly one public completion surface and record which. Two shape facts for the split to dissolve or preserve deliberately: `BashExecSpec.timeoutMs` is required but ignored by `start()` (documented in the seam JSDoc itself), and `stdin`/`env` ride the shared spec for the foreground trusted-plugin path — the carve-up must keep a plain in-process foreground `resolve`+`run` path carrying them, so hook execution is never forced through the long-running runtime. Adjacent blast radius: the credential scrub is duplicated between the two production spawn sites (`packages/bash/bash-local/src/run.ts` and `packages/subagent/subagent-acp/src/run.ts`); if the runtime absorbs spawn-env policy, collapsing that duplication is its work too.
 
 ## Acceptance criteria