Capture file reads in Codex MCP timeline

Detect exec_command events with parsed_cmd.type === "read" and emit
read_file timeline items instead of shell command items. This allows
file reads (via cat, head, tail, etc.) to appear properly in the UI
as file operations rather than generic shell commands.

Changes:
- Add ParsedCmdItemSchema for parsed_cmd array items
- Add parsed_cmd field to ExecCommandBeginEventSchema and ExecCommandEndEventSchema
- Add extractFileReadFromParsedCmd helper to detect file reads
- Update exec_command_begin/end handlers to emit read_file timeline items
- Update test prompt to allow cat-based file reads
- Fix test assertion to find completed (not running) read_file calls

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plan.md

@@ -743,7 +743,7 @@ Build a new Codex MCP provider side‑by‑side with the existing Codex SDK prov
   4. Recommendations for tests that need strengthening
   - **Done (2025-12-25 16:20)**: WHAT: Ran full server test suite (`npm run test --workspace=@paseo/server`), identified 2 workarounds in `packages/server/src/server/agent/providers/codex-mcp-agent.test.ts:797-805` (read_file skip) and `:819-821` (web_search output skip). Created debug scripts `scripts/codex-file-read-debug.ts` and `scripts/codex-websearch-debug.ts` to verify claims. RESULT: **Both claims are FALSE - workarounds are hiding bugs**. (1) File reads ARE exposed via `exec_command_begin/end` with `parsed_cmd[].type === "read"` containing path. (2) Web search results ARE exposed via `mcp_tool_call_end` with results in `result.Ok.content`. EVIDENCE: Full findings in `REPORT-test-audit.md:1`, raw event captures in debug script outputs show `parsed_cmd: [{"type":"read","path":"/tmp/..."}]` and `result: {"Ok":{"content":[{"text":"{\"web\":[...]}"}]}}`. Test results: codex-mcp-agent.test.ts 13/13 passed, codex-agent.test.ts 1 failed + 1 skipped (deprecated SDK).
 
-- [ ] **CRITICAL**: File reads MUST be captured in timeline.
+- [x] **CRITICAL**: File reads MUST be captured in timeline.
 
   The previous agent claimed "Codex MCP doesn't expose read_file tool" and skipped assertions. This is UNACCEPTABLE.
 
@@ -766,6 +766,7 @@ Build a new Codex MCP provider side‑by‑side with the existing Codex SDK prov
   - Test verifies this works
 
   **NO EXCUSES. If Codex reads files, we capture it.**
+  - **Done (2025-12-25 15:07)**: WHAT: Added `ParsedCmdItemSchema` and `parsed_cmd` field to `ExecCommandBeginEventSchema` and `ExecCommandEndEventSchema` in `packages/server/src/server/agent/providers/codex-mcp-agent.ts:643-668`. Added `extractFileReadFromParsedCmd` helper at `packages/server/src/server/agent/providers/codex-mcp-agent.ts:1907-1923` to detect `parsed_cmd.type === "read"` events. Updated `exec_command_begin` handler at `packages/server/src/server/agent/providers/codex-mcp-agent.ts:3222-3258` and `exec_command_end` handler at `packages/server/src/server/agent/providers/codex-mcp-agent.ts:3260-3386` to emit `read_file` timeline items with path input and content output when file reads are detected. Updated test prompt at `packages/server/src/server/agent/providers/codex-mcp-agent.test.ts:725` to allow cat-based file reads, and fixed test assertion at `packages/server/src/server/agent/providers/codex-mcp-agent.test.ts:797-802` to find completed read_file calls. RESULT: File reads now appear as `read_file` timeline items with `server: "file"`, `tool: "read_file"`, `kind: "read"`, file path in input, and file content in output. EVIDENCE: `npm run test --workspace=@paseo/server -- codex-mcp-agent.test.ts` (13 passed, 0 failed), `npm run typecheck --workspace=@paseo/server` (0 errors).
 
 - [ ] **E2E**: Test Codex MCP in the app using Playwright.