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/tools/prdy/prdy-update.sh

@@ -0,0 +1,94 @@
+#!/usr/bin/env bash
+set -euo pipefail
+#
+# prdy-update.sh — Update an existing PRD via guided runtime session
+#
+# Usage:
+#   prdy-update.sh [--project <path>]
+#
+# Launches a dedicated runtime session in yolo mode with a specialized
+# system prompt that reads the existing PRD and guides targeted modifications.
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "$SCRIPT_DIR/_lib.sh"
+
+# ─── Parse arguments ─────────────────────────────────────────────────────────
+
+PROJECT="."
+
+while [[ $# -gt 0 ]]; do
+  case "$1" in
+    --project) PROJECT="$2"; shift 2 ;;
+    -h|--help)
+      cat <<'USAGE'
+prdy-update.sh — Update an existing PRD via guided runtime session
+
+Usage: prdy-update.sh [--project <path>]
+
+Options:
+  --project <path>   Project directory (default: CWD)
+
+Launches the selected runtime in yolo mode with a PRD-update prompt.
+The agent will read the existing docs/PRD.md, summarize its state,
+and ask what changes are needed.
+
+Examples:
+  mosaic prdy update
+  mosaic prdy update --project ~/src/my-app
+USAGE
+      exit 0
+      ;;
+    *) echo "Unknown option: $1" >&2; exit 1 ;;
+  esac
+done
+
+# Expand tilde if passed literally (e.g., --project ~/src/foo)
+PROJECT="${PROJECT/#\~/$HOME}"
+
+# ─── Preflight checks ───────────────────────────────────────────────────────
+
+RUNTIME_CMD="$(prdy_runtime_command)"
+_require_cmd "$RUNTIME_CMD"
+
+# Require existing PRD
+EXISTING="$(find_prd "$PROJECT")"
+if [[ -z "$EXISTING" ]]; then
+  fail "No PRD found in $PROJECT/docs/"
+  echo -e "  Run ${C_CYAN}mosaic prdy init${C_RESET} to create one first."
+  exit 1
+fi
+
+# ─── Build system prompt ─────────────────────────────────────────────────────
+
+step "Launching PRD update session"
+
+SYSTEM_PROMPT="$(build_prdy_system_prompt "update")"
+
+KICKOFF="Read the existing PRD at ${EXISTING}, summarize its current state, then ask what changes or additions are needed."
+
+# ─── Launch runtime ──────────────────────────────────────────────────────────
+
+info "Updating: $EXISTING"
+info "Mode: PRD Update (yolo, runtime: $RUNTIME_CMD)"
+echo ""
+
+cd "$PROJECT"
+if [[ "$RUNTIME_CMD" == "claude" ]]; then
+  exec claude --dangerously-skip-permissions --append-system-prompt "$SYSTEM_PROMPT" "$KICKOFF"
+fi
+
+if [[ "$RUNTIME_CMD" == "codex" ]]; then
+  CODEX_PROMPT="$(cat <<EOF
+Follow this PRD contract exactly.
+
+$SYSTEM_PROMPT
+
+Task:
+$KICKOFF
+EOF
+)"
+  exec codex --dangerously-bypass-approvals-and-sandbox "$CODEX_PROMPT"
+fi
+
+fail "Unsupported runtime: $RUNTIME_CMD"
+exit 1