feat: unify mosaic CLI — single binary, no PATH conflict

- Rename framework bash launcher: mosaic → mosaic-launch
- npm CLI (@mosaic/cli) is now the single 'mosaic' binary on PATH
- Add launcher delegation: mosaic {claude,codex,opencode,pi,yolo}
  delegates to mosaic-launch via execFileSync with inherited stdio
- Add delegated management commands: init, doctor, sync, seq,
  bootstrap, coord, upgrade
- install.sh: remove framework bin PATH requirement, clean up old
  mosaic binary on upgrade, simplified summary output
- framework install.sh: preserve sources/ dir (fixes rsync noise
  about agent-skills)
- session-run.sh: update references to mosaic-launch

Users now only need ~/.npm-global/bin on PATH. The npm CLI finds
mosaic-launch at its absolute path (~/.config/mosaic/bin/mosaic-launch).

packages/mosaic/framework/tools/orchestrator/session-run.sh

@@ -80,11 +80,11 @@ echo -e "${C_CYAN}Capsule:${C_RESET} $(next_task_capsule_path "$PROJECT")"
 
 cd "$PROJECT"
 if [[ "$YOLO" == true ]]; then
-  exec "$MOSAIC_HOME/bin/mosaic" yolo "$runtime" "$launch_prompt"
+  exec "$MOSAIC_HOME/bin/mosaic-launch" yolo "$runtime" "$launch_prompt"
 elif [[ "$runtime" == "claude" ]]; then
-  exec "$MOSAIC_HOME/bin/mosaic" claude "$launch_prompt"
+  exec "$MOSAIC_HOME/bin/mosaic-launch" claude "$launch_prompt"
 elif [[ "$runtime" == "codex" ]]; then
-  exec "$MOSAIC_HOME/bin/mosaic" codex "$launch_prompt"
+  exec "$MOSAIC_HOME/bin/mosaic-launch" codex "$launch_prompt"
 fi
 
 echo -e "${C_RED}Unsupported coord runtime: $runtime${C_RESET}" >&2