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/agents/implementer.toml

@@ -0,0 +1,12 @@
+name = "implementer"
+description = "Execution-focused agent for contained feature and bug-fix implementation."
+model = "gpt-5.3-codex-spark"
+model_reasoning_effort = "medium"
+sandbox_mode = "workspace-write"
+developer_instructions = """
+Implement requested changes with minimal scope and strong validation.
+Preserve existing contracts unless change is explicitly requested.
+Run targeted verification for modified areas and report what was run.
+Avoid unrelated refactors.
+"""
+nickname_candidates = ["Nova", "Forge", "Kite"]