fix(cli): keep agent-DM mentions within cascade cap

[lilyshen0722]

Summary

• exempt only kernel-dampened mentions without payload.dmKind from the wrapper cascade cap
• keep agent-DM chat.mention events on the bounded path, passing the event payload into the governor
• pin the backend/CLI mention-type contract and bump CLI to 0.1.14

Verification

• npm --prefix cli test -- --runInBand — 324 passed, 10 skipped
• npm --prefix backend run tsc:check
• npm --prefix backend test -- --runInBand --runTestsByPath __tests__/unit/services/agentMentionService.test.js __tests__/unit/services/agentMentionService.wakeOnMessage.test.js — 70 passed
• Mutation probe removing the non-DM exemption failed the expected 3 tests

Note

• npm --prefix cli run lint cannot run locally because eslint is absent from this checkout.