Added Codex CLI agent integration, full test coverage (blocked on #281).

[akshan-main]

Closes #245

Registers a codexcli agent package following the same pattern as claudecode and geminicli (self-registration via init(), full Agent interface, TranscriptAnalyzer, TranscriptChunker).

Streaming JSONL parser that extracts thread ID, messages, commands, file changes, and token usage, made tolerant of unknown event types so it won't break when Codex adds new ones.

entire codex exec [flags] -- with --model and --sandbox flags.

Uses the shared DetectFileChanges, FilterAndNormalizePaths, cleanPromptForCommit, and GetGitAuthor; no new abstractions.

• Wrapper not hooks: Codex doesn't expose a lifecycle hook system. The wrapper captures the complete JSONL stream in one shot via codex exec --json, then creates a checkpoint through strategy.SaveChanges().
• Same checkpoint path: SaveContext construction, file change detection, path normalization, and commit message generation all reuse existing shared functions.
• Hard error on checkpoint failure: Consistent with how Claude Code's Stop hook and Gemini's AfterAgent hook handle SaveChanges errors.
• SupportsHooks() returns false: ParseHookInput returns an error stub. The wrapper command replaces the hook lifecycle entirely.

Commands:

entire codex exec [flags] --

--model, -m — Override the Codex model (e.g., 4o)
--sandbox, -s— Sandbox policy (read-only, workspace-write, danger-full-access)

Usage examples:

entire codex exec -- "fix the failing tests"
entire codex exec -m 4o -- "refactor the auth module"
echo "add error handling" | entire codex exec -- -
There's no entire codex start, entire codex stop, entire codex resume, etc., because Codex CLI doesn't have a lifecycle hook system like Claude Code does. The wrapper command runs the full session in one shot: execute Codex, capture the JSONL, save the checkpoint.

This is what user sees in terminal:

Running: codex exec --json ... (stderr)
Codex runs silently (JSONL captured to temp file only)
Saved transcript to: ... (stderr)
Files modified (N): ... (stderr)
Checkpoint saved. (stderr)
Codex's last message/summary printed to stdout

thank you for entire and congratulations on the seed raised

would be great if this can be reviewed, any feedback is welcome @Soph @gtrrz-victor @khaong