docs(rfc): propose nine simplification RFCs from a five-domain survey

Survey of master for surface area whose consumers are tests/docs only,
classified per candidate (production vs non-production corpus, rg + call-site
reads). New proposed/simplification RFCs:

- prune-producerless-vocabulary-variants: CacheHint/cache? fields,
  MessageSource 'agent', TurnTrigger 'continuation' (the TurnEndReasonMap
  omitted-until-emitted policy, applied)
- drop-inert-request-knobs: GenerateOptions.prefill (both adapters throw
  UNSUPPORTED), ToolSchema.strict (zero setters; beta-URL-only feature)
- drop-web-providers-change-event: the llm/adapter-change precedent replayed
- drop-image-content-block: no producer; every consumer silently drops it
- prune-write-only-fs-surface: fs-local STREAM_MIN_SIZE/streamMinSize,
  FsTarget.inputPath, FsEditOutcome.replacements/replaceAll,
  FileReadOutcome.limit/version
- prune-unimplemented-subagent-vocabulary: outputSchema/structured,
  toolFilter, sendMessage/resume (depthLimit stays)
- trim-acp-bridge-unreachable-surface: agentName/agentVersion knobs
  (resolves TODO(double-default)), toolKindFor name-sniffing
- prune-dead-core-spine-surface: SurfaceManager.invalidate(), runLoop/Inbox
  exports, ToolExecutionResult.callId
- share-app-bin-boot-glue: the twin coverage-exempt bin helpers

Also supplements three existing proposed RFCs with survey evidence: the bash
seam consumption census (generic-long-running-tool-runtime), three more
static inventories (discover-package-inventory), and the bridge's already-1:1
id usage (unify-agent-and-session-id).

docs/rfc/proposed/process/2026-06-20-discover-package-inventory.md

@@ -4,7 +4,7 @@ Status: proposed
 
 ## Problem
 
-Package and gate inventories are repeated by hand. The [package cookbook](../../../cookbook/adding-a-package.md) tells authors to update several files. The [package README](../../../../packages/README.md) carries a hand-written dependency graph. [CI](../../../../.github/workflows/ci.yml) and [development docs](../../../development.md) can drift from the actual `doc-sync` subcommands when new gates are added. `tsconfig.build.json` lists all 18 packages as explicit project `references`. These lists are small today, but every new package or gate creates another manual synchronization point.
+Package and gate inventories are repeated by hand. The [package cookbook](../../../cookbook/adding-a-package.md) tells authors to update several files. The [package README](../../../../packages/README.md) carries a hand-written dependency graph. [CI](../../../../.github/workflows/ci.yml) and [development docs](../../../development.md) can drift from the actual `doc-sync` subcommands when new gates are added. `tsconfig.build.json` and the root `tsconfig.json` each hand-list every package as explicit project `references`. `knip.json` restates a per-package `entry` stanza for each package that gains an `*.e2e.ts` suite — byte-identical overrides that exist only because the shared `packages/*/*` stanza omits the e2e glob (an entry glob matching no files is inert, so the default stanza could carry it for every package). The ACP snapshot suite's scenario table (`examples/acp-agent/tests/acp.snapshot.ts`) hand-maintains a `childSessions` count per scenario that duplicates the number of `session.<n>.jsonl` fixture siblings on disk. These lists are small today, but every new package or gate creates another manual synchronization point.
 
 The [package hierarchy](../../implemented/architecture/2026-06-20-package-hierarchy.md) already removed several of these by hand: `scripts/publint-all.ts` now derives its list from the `packages/<group>/<pkg>` layout, and the two `tsconfig` `paths` maps collapsed to one `@deepseek-ai/dsh-*` wildcard. What remains is the inventory that cannot be globbed away — chiefly `tsconfig.build.json`'s project `references`, which TypeScript requires as an explicit array (no wildcard form).
 
@@ -16,12 +16,16 @@ Make the remaining package/gate inventories discoverable. A single canonical sou
 
 The hierarchy does not need to encode every fact about a package, but it should encode the broad maintenance policy: core/product packages, integrations, capability seams, and support/test/example packages should not all require a hand-maintained exception list before scripts can tell them apart.
 
+Two of the cataloged items need no generator at all: folding the e2e entry glob into knip's default stanza deletes the per-package restatements outright, and `childSessions` can be discovered from each scenario's fixture directory, leaving the scenario table to declare only policy (`recorded`, `hasModelTurn`).
+
 ## Acceptance criteria
 
 - `tsconfig.build.json` project `references` are generated from the hierarchy (a generator emits them; a `--check` gate fails when the committed copy is stale), rather than hand-maintained.
 - Adding a package does not require editing a static package list for any gate.
 - Docs describe the source of truth rather than repeating generated inventories.
 - CI invokes the aggregate commands and lets those commands own their sub-gate lists.
+- `knip.json` carries a per-package override only where it encodes real information (an extra entry file, an ignored dependency), never a restatement of the default stanza.
+- Snapshot scenarios declare policy, not facts discoverable from their fixture directories.
 
 ## What we give up