feat(agent): interactive TUI launcher + identity + TOOLS.md (#35)

- scripts/agent.sh <name>: launches interactive pi TUI in the container
  with contracts + optional mission + agent identity + named session +
  optional workspace/tools; the Mosaic alternative to vanilla pi
- pi adapter: MOSAIC_INTERACTIVE branch (clean TUI, no -p, no initial
  prompt); headless exec rebuilt via positional args (no word-splitting
  on the request); MOSAIC_AGENT_NAME optional in headless
- loader: AGENT IDENTITY section when the launcher names the agent
- compose: fixed command removed (request defaults live in run-agent.sh);
  MOSAIC_INTERACTIVE/MOSAIC_AGENT_NAME passthrough
- docs/TOOLS.md: full on-demand tool reference; AGENTS.md routes to it
- RELEASE -> 0.0.8 (container change); build verified

Closes #35

AGENTS.md

@@ -69,9 +69,13 @@ green at every step. Not production software — a proven foundation.
 `verify.sh` · `run-task.sh run <task.json>` · `release.sh
 package|activate|rollback|status` · `reset.sh` (**danger**: wipes the data
 root; triple-safety-checked) · `mosaic-task.mjs validate|run|show|list|retry|prune` ·
+`agent.sh <name>` (interactive TUI agent) ·
 suites: `test-config.sh`, `test-task.sh`, `test-release.sh`,
 `test-conductor.sh`.
 
+Full reference — usage, fields, exit codes, safety notes:
+`docs/TOOLS.md` (read on demand; do not rely on this summary for detail).
+
 ## Data map (canon)
 
 - `~/.config/mosaic-dev/config.json` — system config (user-authored; never