refactor(acp): reduce bridge to automation protocol

docs/testing.md

@@ -7,7 +7,7 @@ How this repo tests, tier by tier, and the rules that keep a green suite meaning
 - **Unit** (`pnpm run test`): vitest over `packages|examples/*/tests/**/*.spec.ts`, colocated with what they test. Every registry gets an HMR-safety test (dispose the contributing fiber, assert cleanup). Prefer edge cases, error paths, event ordering, concurrency races, and permanent contract regressions (see `packages/core/agent-loop/tests/contract-regressions.spec.ts`).
 - **Coverage gate** (`pnpm run test:coverage`): the gating run, per-file 100% on `packages/*/*/src`. An uncovered line is often dead code the gate is correctly flagging for deletion, not a missing test to bolt on. Line coverage is necessary, never sufficient — it proves lines ran, not that the feature works as shipped.
 - **Real-API e2e** (`pnpm run test:e2e`): with-key tests against live provider APIs — the DeepSeek model plus provider-specific smokes that gate on their own keys (`EXA_API_KEY`, `PERPLEXITY_API_KEY`, …); each suite self-skips without its key so keyless CI stays green ([real-API e2e Agent Note](../.agents/notes/implemented/testing/2026-06-19-real-api-e2e-ci.md)).
-- **Snapshot** (`pnpm run test:snapshot`): transport-specific keyless expected outputs cover external presentation. ACP suites boot the real example subprocess, replay a recorded session, and diff normalized JSON-RPC plus the re-persisted log ([ACP snapshot Agent Note](../.agents/notes/implemented/testing/2026-06-19-acp-snapshot-tests.md)); the headless suite independently pins `stream-json` through its real one-shot subprocess. TUI completed journeys replay recorded primary/child JSONL through the real agent loop and tools before projecting ANSI into semantic terminal-state expected outputs; package-local snapshots retain transient renderer states, and a real PTY conversation covers the process boundary ([TUI snapshot Agent Note](../.agents/notes/implemented/testing/2026-07-18-tui-terminal-state-snapshots.md)). Use `pnpm run test:snapshot:record` when a model transcript must change and `pnpm run test:snapshot:refresh` when committed replay input remains correct; review every JSONL and expected-output diff. System-prompt/tool-schema content is pinned by one ACP scenario (`text-turn`) and tokenized in every other fixture, so a prompt or schema edit churns one committed line ([pinned-header Agent Note](../.agents/notes/implemented/testing/2026-07-06-pin-request-header-content-in-one-scenario.md)).
+- **Snapshot** (`pnpm run test:snapshot`): transport-specific keyless expected outputs cover protocol or presentation behavior, while persisted logs pin assembled backend behavior. ACP suites boot the real automation server subprocess, replay a recorded session, and diff normalized JSON-RPC plus the re-persisted log ([ACP snapshot Agent Note](../.agents/notes/implemented/testing/2026-06-19-acp-snapshot-tests.md)); the headless suite independently pins `stream-json` through its real one-shot subprocess. TUI completed journeys replay recorded primary/child JSONL through the real agent loop and tools before projecting ANSI into semantic terminal-state expected outputs; package-local snapshots retain transient renderer states, and a real PTY conversation covers the process boundary ([TUI snapshot Agent Note](../.agents/notes/implemented/testing/2026-07-18-tui-terminal-state-snapshots.md)). Use `pnpm run test:snapshot:record` when a model transcript must change and `pnpm run test:snapshot:refresh` when committed replay input remains correct; review every JSONL and expected-output diff. System-prompt/tool-schema content is pinned by one ACP scenario (`text-turn`) and tokenized in every other fixture, so a prompt or schema edit churns one committed line ([pinned-header Agent Note](../.agents/notes/implemented/testing/2026-07-06-pin-request-header-content-in-one-scenario.md)).
 
 ## The with-key policy: inference is cheap here
 
@@ -41,4 +41,4 @@ An e2e assertion re-runs the command or re-reads the file externally; a keyword
 
 ## When a snapshot test is required
 
-Every non-trivial model- or human-visible change adds or updates a keyless scenario in the same PR through a runnable example's owning snapshot suite. Package tests, e2e assertions, mock/test-only compositions, and PR rationale do not replace the assembled transcript; extend the harness when needed. ACP surfaces use `examples/<name>/tests/snapshots/`, a scenario table over the [`dsh-acp-snapshot`](../packages/support/acp-snapshot/README.md) suite factory (`examples/acp-agent` is primary); `examples/headless-agent` owns the `stream-json` snapshot and replay fixtures. Completed interactive-terminal journeys use JSONL-driven scenarios under `examples/tui-agent/tests/snapshots/`; transient presentation uses the package-local semantic matrix, with a PTY case when input, Loader selection, or terminal teardown changes. New capability seams, lifecycle shapes, or transcript surfaces name every coverage tier at plan time and verify the harness can express it before implementation.
+Every non-trivial model-, protocol-, or human-visible change adds or updates a keyless scenario in the same PR through a runnable example's owning snapshot suite. Package tests, e2e assertions, mock/test-only compositions, and PR rationale do not replace the assembled transcript; extend the harness when needed. ACP automation scenarios use `examples/<name>/tests/snapshots/`, a scenario table over the [`dsh-acp-snapshot`](../packages/support/acp-snapshot/README.md) suite factory (`examples/acp-agent` is primary); `examples/headless-agent` owns the `stream-json` snapshot and replay fixtures. Completed interactive-terminal journeys use JSONL-driven scenarios under `examples/tui-agent/tests/snapshots/`; transient presentation uses the package-local semantic matrix, with a PTY case when input, Loader selection, or terminal teardown changes. New capability seams, lifecycle shapes, or transcript surfaces name every coverage tier at plan time and verify the harness can express it before implementation.