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

compose.yaml

@@ -21,6 +21,9 @@ services:
       # Persistent named session dir + optional fork source (M6/M11)
       MOSAIC_SESSION_DIR: ${MOSAIC_SESSION_DIR:-}
       MOSAIC_SESSION_FORK: ${MOSAIC_SESSION_FORK:-}
+      # Interactive TUI mode + agent identity (M13, set by scripts/agent.sh)
+      MOSAIC_INTERACTIVE: ${MOSAIC_INTERACTIVE:-}
+      MOSAIC_AGENT_NAME: ${MOSAIC_AGENT_NAME:-}
       # mock adapter only: verbatim response for deterministic seam tests
       MOSAIC_MOCK_RESPONSE: ${MOSAIC_MOCK_RESPONSE:-}
       # Documented container auth alternative: provider API key via
@@ -34,6 +37,6 @@ services:
       # Runtime credential only: pi auth file mounted READ-ONLY.
       # Never copied into the image.
       - ${PI_AUTH_FILE:-/home/jwoltje/.pi/agent/auth.json}:/home/node/.pi/agent/auth.json:ro
-    # One-shot: the exact startup verification request. It deliberately
-    # does NOT contain the expected marker MOSAIC_HELLO_OK.
-    command: ["Return your startup marker and nothing else."]
+    # Headless runs: the request is passed as command args by the launchers
+    # (run-task.sh) or defaults inside run-agent.sh (hello/verify). Never a
+    # fixed command here - interactive runs (scripts/agent.sh) need no args.