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

scripts/agent.sh

@@ -0,0 +1,67 @@
+#!/usr/bin/env bash
+# Launch an interactive (TUI) Mosaic agent in its container.
+#
+# Usage:
+#   scripts/agent.sh <name> [--mission <file>] [--workspace <ws>]
+#                    [--session <name>] [--tools <comma,list>]
+#
+# The agent receives the four immutable contracts (constitution, standards,
+# SOUL, USER) plus its own identity and optional mission directives as its
+# system prompt, a persistent named session, and - if declared - a
+# workspace and tool capabilities. The TUI opens clean; you drive.
+#
+# This is the Mosaic alternative to launching vanilla pi: same engine,
+# governed context.
+set -euo pipefail
+cd "$(dirname "$0")/.."
+# shellcheck source=common.sh
+source scripts/common.sh
+
+NAME=""
+MISSION=""
+WORKSPACE=""
+SESSION=""
+TOOLS=""
+
+while [ $# -gt 0 ]; do
+    case "$1" in
+        --mission)   MISSION="${2:?}"; shift 2 ;;
+        --workspace) WORKSPACE="${2:?}"; shift 2 ;;
+        --session)   SESSION="${2:?}"; shift 2 ;;
+        --tools)     TOOLS="${2:?}"; shift 2 ;;
+        --help|-h)   sed -n '2,12p' "$0"; exit 0 ;;
+        *)           NAME="$1"; shift ;;
+    esac
+done
+
+[ -n "$NAME" ] || { echo "agent: usage: scripts/agent.sh <name> [--mission f] [--workspace ws] [--session s] [--tools list]" >&2; exit 4; }
+case "$NAME" in *[!A-Za-z0-9._-]*|'') echo "agent: invalid agent name" >&2; exit 4;; esac
+
+load_config
+load_release
+bootstrap_runtime_dir
+
+SESSION="${SESSION:-agent-$NAME}"
+mkdir -p "$MOSAIC_DEV_DIR/sessions/$SESSION"
+export MOSAIC_SESSION_DIR="/var/lib/mosaic/sessions/$SESSION"
+export MOSAIC_AGENT_NAME="$NAME"
+export MOSAIC_INTERACTIVE=1
+export MOSAIC_TOOLS="${TOOLS:+$TOOLS}"
+
+if [ -n "$MISSION" ]; then
+    [ -r "$MISSION" ] || { echo "agent: mission file not readable: $MISSION" >&2; exit 4; }
+    mkdir -p "$MOSAIC_DEV_DIR/agent-missions"
+    cp "$MISSION" "$MOSAIC_DEV_DIR/agent-missions/$NAME.json"
+    export MOSAIC_MISSION_FILE="/var/lib/mosaic/agent-missions/$NAME.json"
+fi
+
+if [ -n "$WORKSPACE" ]; then
+    case "$WORKSPACE" in *[!A-Za-z0-9._-]*|'') echo "agent: invalid workspace name" >&2; exit 4;; esac
+    mkdir -p "$MOSAIC_DEV_DIR/workspaces/$WORKSPACE"
+    export MOSAIC_WORKSPACE="/var/lib/mosaic/workspaces/$WORKSPACE"
+fi
+
+echo "agent: launching TUI agent '$NAME' (session: $SESSION, adapter: $MOSAIC_ADAPTER, model: $MOSAIC_MODEL)"
+echo "agent: contracts + $([ -n "$MISSION" ] && echo 'mission' || echo 'no mission') loaded; exit the TUI with /quit"
+# No -T: the TTY is the point. Ctrl+C twice or /quit exits.
+exec docker compose run --rm mosaic-agent