fix(herdr): resolve shim routing defects, add workspace scoping, and bump to v3.0.1

- Resolve Herdr shim 5 routing & paste defects (ISSUE-1 ~ ISSUE-5):
  * paste-buffer: use pane send-text without auto-enter, propagate rc=3 to send_keys_safe
  * exact-match pane resolution: remove substring matching ('in tn') across all branches
  * workspace scoping: introduce HERDR_WORKSPACE_ID and .mam/herdr_workspace_id persistence
  * unified resolver: single _resolve_herdr_pane_id helper across shim commands
- Resolve dialog token false-positive on 'Yes, try it' tip and isolate fullscreen modal rejection
- Sync mock Herdr CLI contracts in tests/conftest.py
- Add contract tests H-15~H-23 and regression tests D-4~D-7 (412 tests, 100% PASS)
- Add multi-agent loop plans, review reports, and bug report
- Update framework and skill packages to v3.0.1

.mam.env.example

@@ -48,6 +48,12 @@
 #default: $HOME/.config/herdr/herdr.sock
 # HERDR_SOCKET_PATH=$HOME/.config/herdr/herdr.sock
 
+# Explicit Herdr workspace scope identifier (`herdr pane list --workspace <id>`).
+# Hard filters pane/agent resolution to this workspace. When unset, falls back
+# to $WORKSPACE_ROOT/.mam/herdr_workspace_id or server-global resolution.
+#default: <unset> (uses persisted .mam/herdr_workspace_id or global)
+# HERDR_WORKSPACE_ID=w1
+
 # ===========================================================================
 # delegate-job / MQTT broker
 # ===========================================================================