feat: Claude Code Monitor — lanes, pipelines and a merged workspace

Internal SmartGift build of a Claude Code monitoring dashboard.

Lanes: a durable unit of parallel agent work, one per working directory,
tracked across session restarts. Managed lanes are git worktrees the
dashboard provisions and can reset or remove behind a three-check destroy
guard and a counted preflight; adopted lanes are directories you already
own and are never destroyable.

Pipelines: a lane moves through pipeline stages. A stage the agent declares
with evidence renders green; a stage inferred from the tool-event stream
renders dashed amber and never counts as done. Detection is forward-only
within a 30-minute window, and never writes the declared stage.

Workspace: one page at /run with a lane grid, the selected lane's pipeline,
and a full Claude console behind a disclosure.

.codex/README.md

@@ -0,0 +1,29 @@
+# Codex Agent Setup
+
+This directory contains all project-scoped Codex extensions:
+
+- instruction baseline via root [`AGENTS.md`](../AGENTS.md)
+- execution policy rules in [`rules/default.rules`](./rules/default.rules)
+- custom subagent definitions in [`agents/`](./agents)
+- reusable skills in [`skills/`](./skills)
+- runtime configuration in [`config.toml`](./config.toml)
+
+## What Codex reads
+
+- `AGENTS.md` from repository root
+- `.codex/config.toml` for runtime settings
+- `.codex/agents/*.toml` for custom agents
+- `.codex/skills/*/SKILL.md` for project skills
+- `.codex/rules/*.rules` for execution policy
+
+## Included custom agents
+
+- `reviewer`: read-only, high-rigor review agent
+- `implementer`: workspace-write implementation agent
+- `release_auditor`: read-only release readiness checker
+
+## Included skills
+
+- `repo-onboarding` — architecture discovery and verification selection
+- `mcp-maintainer` — MCP server operations and troubleshooting
+- `release-guard` — release readiness checks