feat: integrate framework files into monorepo under packages/mosaic/framework/

Moves all Mosaic framework runtime files from the separate bootstrap repo
into the monorepo as canonical source. The @mosaic/mosaic npm package now
ships the complete framework — bin scripts, runtime configs, tools, and
templates — enabling standalone installation via npm install.

Structure:
  packages/mosaic/framework/
  ├── bin/          28 CLI scripts (mosaic, mosaic-doctor, mosaic-sync-skills, etc.)
  ├── runtime/      Runtime adapters (claude, codex, opencode, pi, mcp)
  ├── tools/        Shell tooling (git, prdy, orchestrator, quality, etc.)
  ├── templates/    Agent and repo templates
  ├── defaults/     Default identity files (AGENTS.md, STANDARDS.md, SOUL.md, etc.)
  ├── install.sh    Legacy bash installer
  └── remote-install.sh  One-liner remote installer

Key files with Pi support and recent fixes:
- bin/mosaic: launch_pi() with skills-local loop
- bin/mosaic-doctor: --fix auto-wiring for all 4 harnesses
- bin/mosaic-sync-skills: Pi as 4th link target, symlink-aware find
- bin/mosaic-link-runtime-assets: Pi settings.json patching
- bin/mosaic-migrate-local-skills: Pi skill roots, symlink find
- runtime/pi/RUNTIME.md + mosaic-extension.ts

Package ships 251 framework files in the npm tarball (278KB compressed).

packages/mosaic/framework/templates/repo/scripts/agent/session-start.sh

@@ -0,0 +1,92 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=./common.sh
+source "$SCRIPT_DIR/common.sh"
+
+ensure_repo_root
+load_repo_hooks
+
+if git rev-parse --is-inside-work-tree >/dev/null 2>&1 && has_remote; then
+  if git diff --quiet && git diff --cached --quiet; then
+    run_step "Pull latest changes" git pull --rebase
+  else
+    echo "[agent-framework] Skip pull: working tree has local changes"
+  fi
+fi
+
+# ─── Mission state detection (ORCHESTRATOR-PROTOCOL) ────────────────────────
+ORCH_DIR=".mosaic/orchestrator"
+MISSION_JSON="$ORCH_DIR/mission.json"
+COORD_LIB="$HOME/.config/mosaic/tools/orchestrator/_lib.sh"
+
+if [[ -f "$MISSION_JSON" ]] && command -v jq &>/dev/null; then
+  mission_status="$(jq -r '.status // "inactive"' "$MISSION_JSON")"
+
+  if [[ "$mission_status" == "active" || "$mission_status" == "paused" ]]; then
+    mission_name="$(jq -r '.name // "unnamed"' "$MISSION_JSON")"
+    echo ""
+    echo "========================================="
+    echo "ACTIVE MISSION DETECTED"
+    echo "========================================="
+    echo "  Mission: $mission_name"
+
+    # Extract key fields from manifest if present
+    manifest="docs/MISSION-MANIFEST.md"
+    if [[ -f "$manifest" ]]; then
+      phase="$(grep -m1 '^\*\*Phase:\*\*' "$manifest" 2>/dev/null | sed 's/.*\*\*Phase:\*\* //' || true)"
+      milestone="$(grep -m1 '^\*\*Current Milestone:\*\*' "$manifest" 2>/dev/null | sed 's/.*\*\*Current Milestone:\*\* //' || true)"
+      progress="$(grep -m1 '^\*\*Progress:\*\*' "$manifest" 2>/dev/null | sed 's/.*\*\*Progress:\*\* //' || true)"
+      [[ -n "$phase" ]] && echo "  Phase: $phase"
+      [[ -n "$milestone" ]] && echo "  Milestone: $milestone"
+      [[ -n "$progress" ]] && echo "  Progress: $progress"
+    fi
+
+    # Task counts
+    if [[ -f "docs/TASKS.md" ]]; then
+      total="$(grep -c '^|' "docs/TASKS.md" 2>/dev/null || true)"
+      total="${total:-0}"
+      done_count="$(grep -ci '| done \|| completed ' "docs/TASKS.md" 2>/dev/null || true)"
+      done_count="${done_count:-0}"
+      approx_total=$(( total > 2 ? total - 2 : 0 ))
+      echo "  Tasks: ~${done_count} done of ~${approx_total} total"
+    fi
+
+    # Scratchpad
+    if [[ -d "docs/scratchpads" ]]; then
+      latest_sp="$(ls -t docs/scratchpads/*.md 2>/dev/null | head -1 || true)"
+      [[ -n "$latest_sp" ]] && echo "  Scratchpad: $latest_sp"
+    fi
+
+    echo ""
+    echo "  Resume: Read manifest + scratchpad before taking action."
+    echo "  Protocol: ~/.config/mosaic/guides/ORCHESTRATOR-PROTOCOL.md"
+    echo "========================================="
+    echo ""
+
+    # Register session if coordinator lib is available
+    if [[ -f "$COORD_LIB" ]]; then
+      # shellcheck source=/dev/null
+      source "$COORD_LIB"
+      sess_id="$(next_session_id ".")"
+      runtime="${MOSAIC_RUNTIME:-unknown}"
+      session_lock_write "." "$sess_id" "$runtime" "$$"
+
+      # Append session to mission.json
+      updated="$(jq \
+        --arg sid "$sess_id" \
+        --arg rt "$runtime" \
+        --arg ts "$(iso_now)" \
+        '.sessions += [{"session_id":$sid,"runtime":$rt,"started_at":$ts,"ended_at":"","ended_reason":"","milestone_at_end":"","tasks_completed":[],"last_task_id":""}]' \
+        "$MISSION_JSON")"
+      echo "$updated" > "$MISSION_JSON.tmp" && mv "$MISSION_JSON.tmp" "$MISSION_JSON"
+    fi
+  fi
+fi
+
+if declare -F mosaic_hook_session_start >/dev/null 2>&1; then
+  run_step "Run repo start hook" mosaic_hook_session_start
+else
+  echo "[agent-framework] No repo start hook configured (.mosaic/repo-hooks.sh)"
+fi