fix(lanes): auto-detect and report stage for codex lanes (issue 11)

A lane on the 16-node `ship-feature` template showed an untouched pipeline
map and never declared a stage. Four independent causes, fixed at their
shared choke points:

1. Codex emits no hooks, so `touchLaneFromHook` — the only caller of
   `stage-detect.detect()`, and correctly pinned to `claude` — could never
   see a `codex` lane. New `server/lib/codex-ingest.js` tails Codex's own
   rollout journals (`$CODEX_HOME/sessions/**/rollout-*.jsonl`), maps its
   tool calls onto the hook-shaped `{tool_name, tool_input}` the matcher
   already understands, and feeds the existing detect path plus an
   idle/running status mirror under the same guard hooks use. Polled every
   `DASHBOARD_CODEX_POLL_MS` ms (default 15000, `0` disables).
2. `resolveLaneArg` matched on cwd alone, so with a claude and a codex lane
   at one directory (the composite `idx_lanes_cwd_tool`) a `ccam stage`
   call could drive the sibling lane's card. It now resolves by
   `--lane` → `CCAM_LANE_ID` → `--tool`/harness marker → owning lane, and
   errors naming both candidates rather than picking one. Every pane the
   dashboard starts carries `CCAM_LANE_ID` (`tmux new-session -e`, or an
   assignment prefix when typing into a live shell pane).
3. `recordDetection`'s declared-wins veto had no exit: a lane left at the
   pipeline's last node rejected every detection for the rest of its life.
   A declaration on the LAST node no longer vetoes — the pipeline is over
   there, so a later detection is new work. Nothing else is relaxed, and
   detection still never writes `stage` nor renders `done`.
4. The run console pre-filled the pipeline's Claude slash command into
   codex panes, which Codex reads as prose — so the skill that would have
   called `ccam stage` never ran. Claude lanes only now.

A codex lane's *declared* stage still depends on the session calling
`ccam stage`; `AGENTS.md` is the only lever CCAM has, so it now says so.

Verified: server 1345/1345, client 441/441, and end-to-end against a real
codex lane row (detected_stage/detected_signal set, declared stage
untouched, no node rendered done).

AGENTS.md

@@ -11,6 +11,36 @@
 - Update docs whenever workflow or architecture changes — follow `skills/update-project-docs/` automatically at the end of every change-set (README + VN/CN/KO mirrors, ARCHITECTURE, wiki + i18n + cache bump, server/client READMEs, docs/*).
 - Every applicable source file you create or update (`.js/.ts/.tsx/.cjs/.mjs/.py/.sh/.css`) must start with the authorship header: a truthful file overview plus the exact line `@author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>`. See `skills/file-headers/` and `.claude/rules/file-headers.md`; verify with `bash skills/file-headers/scripts/check-headers.sh`.
 
+## Declare your lane stage as you work
+
+This repository is watched by CCAM, its own dashboard. A **lane** is keyed by
+working directory, and the pipeline map only moves forward when the agent doing
+the work declares its stage:
+
+```bash
+ccam stage <stage> --tool codex --evidence "<what is actually done>"
+```
+
+- Call it at every real transition — starting to plan, starting to implement,
+  running tests, opening the PR — not once at the end.
+- Stage names, `default` template: `intake → plan → implement → tests → review
+  → gate → ship → done` (the 16-node `ship-feature` template accepts these as
+  aliases too; `ccam stage` warns on stderr and names the valid nodes if a stage
+  matches none).
+- **`--tool codex` matters.** One directory can back both a `claude` lane and a
+  `codex` lane, and without a tool the command fails rather than guess (it names
+  both candidates). Inside a pane the dashboard started you need nothing — that
+  pane carries `CCAM_LANE_ID`, which outranks everything but `--lane`.
+- If `ccam stage` reports that no lane owns the directory, this checkout was
+  never adopted: skip the stage calls and carry on. Stage reporting is
+  reporting, never control flow — a failed `ccam stage` never justifies skipping
+  a step of the actual work.
+
+The dashboard also *infers* your stage from your tool calls (it reads Codex's
+own rollout journals — see `docs/LANES.md#stage-detection`), but an inference
+only paints a dashed amber badge. It never counts as evidence and never renders
+a node green. Only your own declaration does.
+
 ## Where to work
 - `server/` for API/routes/data processing.
 - `client/` for React UI behavior.