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

AGENTS.md

@@ -81,6 +81,12 @@ packages/    Harness packages, grouped by role at packages/<group>/<pkg>/.
     hook-protocol/  shared Claude Code / Codex hook wire-protocol core (library,
                     not a plugin): matcher primitive, exit-code/stdout codec,
                     runHook (via ctx.bash), most-restrictive merge, hook/* events
+    hooks-claude/   bridge plugin: runs a Claude Code hooks.json / settings on the
+                    interception seams (CC dialect — env + ${CLAUDE_PLUGIN_ROOT}
+                    substitution, per-event stdin payloads, outcome→Decision map)
+    hooks-codex/    bridge plugin: runs a Codex hooks.json on the seams (Codex
+                    dialect — a 5-event, regex-only, block-only, no-substitution
+                    subset of the CC protocol)
   session-persistence/   persistence capability family
     session-persistence/         durable persistence seam + write coordinator
     session-persistence-jsonl/    JSONL-sidecar backend