feat(hooks): dsh-hooks-claude + dsh-hooks-codex bridges (hooks stack PR-F)

The two bridge plugins that run a user's existing Claude Code / Codex hook
config on the harness's typed interception seams, built on the shared
dsh-hook-protocol library. A bridge is a faithfulness adapter, not a power
tool: anything it does a native cordis plugin does more powerfully — the
bridge exists only to run UNMODIFIED external hooks.

- dsh-hooks-claude: CC dialect. Seven hook points (SessionStart,
  UserPromptSubmit, PreToolUse, PostToolUse, Stop, SubagentStart,
  SubagentStop), CC per-event stdin payloads, env + ${CLAUDE_PLUGIN_ROOT}/
  ${CLAUDE_PROJECT_DIR} substitution, literal-or-regex matcher.
- dsh-hooks-codex: Codex dialect — a deliberate subset. Five hook points,
  always-regex matcher, snake_case payloads (turn_id/model, no trailing
  newline), no env/substitution, block-only decisions.

Both map the neutral merged outcome onto the seam's typed Decision and stamp
an explicit {kind:'plugin'} source on injected context (so it is never
mislabeled as a user prompt). Config parse-failure is contained; only command
hooks run. updatedInput is logged+warned (input rewrite deferred); the Stop
loop-guard is deferred (TODO).

Tests: per-file 100% — config-parse unit branches + per-seam mappings
end-to-end through the REAL loop + REAL bash + REAL shell scripts (scripted
mock model only) + a real-Loader export-shape guard. A keyless ACP snapshot
scenario (hook-prompt-block) proves a UserPromptSubmit hook blocks a prompt
end-to-end (rejected turn -> ACP cancelled, hook/* events in the log); a
with-key e2e (hooks.e2e.ts) proves a PreToolUse hook blocks real bash
(verified on disk). The snapshot normalizer now scrubs hook/result.durationMs.

RFC: docs/rfc/implemented/feature/2026-06-30-hook-bridges.md

packages/hooks/hooks-claude/README.md

@@ -0,0 +1,51 @@
+# @deepseek-ai/dsh-hooks-claude
+
+A cordis plugin that runs a user's existing **Claude Code** hook config (a `hooks.json`, or a settings file's `hooks` key) on the harness's canonical interception seams. It is the **CC dialect** half of the hooks subsystem: it owns CC's per-event stdin payloads, CC's env + `${CLAUDE_PLUGIN_ROOT}`/`${CLAUDE_PROJECT_DIR}` substitution, and the mapping from a hook's neutral outcome onto the harness's typed Decisions. The dialect-agnostic primitives (matcher, exit-code/stdout codec, `ctx.bash` execution, most-restrictive merge, the `hook/*` events) come from [`@deepseek-ai/dsh-hook-protocol`](../hook-protocol/README.md).
+
+A native cordis plugin could do everything this bridge does — more powerfully, with typed returns and no serialization boundary. **The bridge exists only to run UNMODIFIED external CC hooks faithfully**; anything bespoke should be a native plugin on the same seams (see [the interception-seams RFC](../../../docs/rfc/implemented/feature/2026-06-30-interception-seams.md)).
+
+## Config
+
+```ts
+import type { Config } from '@deepseek-ai/dsh-hooks-claude'
+const config: Config = {
+  configPath: '/path/to/hooks.json', // required: a hooks.json or a settings file with a `hooks` key
+  pluginRoot: '/path/to/plugin',     // optional: replaces ${CLAUDE_PLUGIN_ROOT} in command strings
+  projectDir: '/path/to/project',    // optional: replaces ${CLAUDE_PROJECT_DIR} AND set as the hook env var
+  defaultTimeoutMs: 600_000,         // optional: per-hook timeout when a hook sets none (CC default)
+}
+```
+
+In a `cordis.yml`:
+
+```yaml
+- dsh-hooks-claude:
+    configPath: ./.claude/hooks.json
+    pluginRoot: ./.claude/plugins/my-plugin
+    projectDir: .
+```
+
+The config is parsed **once** at load. A read/parse failure is contained — the bridge logs a warning and registers nothing rather than crashing boot (a typo'd path must not take the agent down). Only `type: 'command'` hooks run; a `prompt`/`agent`/HTTP hook is parsed-and-skipped with a warning.
+
+## Hook points → seam Decisions
+
+| CC hook | Harness seam | Mapping |
+|---|---|---|
+| `SessionStart` | `agent/session-start` (emit) | additionalContext → `agent.inject()` into the new session (cannot block) |
+| `UserPromptSubmit` | `agent/prompt-submit` (waterfall) | `deny` → `PromptDecision.block`; additionalContext → `allow` with context |
+| `PreToolUse` | `tools/pre-execute` (waterfall) | `deny` → `PreToolDecision.deny`; `ask` → `PreToolDecision.ask` |
+| `PostToolUse` | `tools/post-execute` (waterfall) | `deny` → `block` with feedback; additionalContext → `accept` with context |
+| `Stop` | `agent/turn-continuation` (waterfall) | a blocking Stop hook forces `continue`, feeding its reason as next-step steering |
+| `SubagentStart` | `subagent/start` (emit) | additionalContext → `agent.inject()` into the live child |
+| `SubagentStop` | `subagent/end` (emit) | observe-only |
+
+The matcher subject is the tool name (`PreToolUse`/`PostToolUse`), the session source (`SessionStart`), or the child's agent type (`SubagentStart`/`SubagentStop`); `UserPromptSubmit`/`Stop` ignore matchers. Multiple file-configured hooks on one point run concurrently and fold most-restrictively (`deny > ask > allow`, see `dsh-hook-protocol`).
+
+## Context source
+
+Injected context carries an explicit `{ kind: 'plugin', plugin: 'hooks-claude' }` source. `agent.inject()` defaults a missing source to `{ kind: 'user' }`, which would mislabel plugin context as a user prompt — so the bridge always names itself.
+
+## Deferred (faithful-but-degraded)
+
+- **`updatedInput` (tool-input rewrite)** is logged + warned, **not honored** — input rewrite is a deferred consistency-design problem ([the pre-tool-input-rewrite RFC](../../../docs/rfc/proposed/feature/2026-06-30-pre-tool-input-rewrite.md)).
+- **Stop loop-guard.** CC breaks an infinite force-continue with `stop_hook_active` (true once a Stop hook has fired this run) plus a max-consecutive cap; both are deferred (`TODO(stop-loop-guard)`). Today `stop_hook_active` is always `false`, so a Stop hook that unconditionally blocks would force-continue every step — a hook author must self-limit until the guard lands.