chore(tickets): clôture #165 #166 + épic #161 — sync miroir tickets

#165 (seam plugin slash-commands) et #166 (dispatch e2e du callback plugin)
fermés après merge de feature/165-plugin-slash-commands dans develop.
L'épic #161 (commandes slash custom CLI) est entièrement terminé : tous ses
sous-tickets (#162 fondation, #163 autocomplete, #164 /profile, #165 seam
plugin) plus le dispatch e2e (#166) sont intégrés.
Sync du miroir local + counter (#166 créé).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.ideai/tickets/165/issue.md

@@ -2,16 +2,16 @@
 id: "2b41b7d3-b362-4e8d-8c56-c92b429da1f7"
 number: 165
 title: "SDK/plugins: allow plugins to contribute custom CLI slash commands"
-status: "open"
+status: "closed"
 priority: "medium"
 sprint: null
 links: [{"target":"#162","kind":"dependsOn"}]
 agentRefs: [{"agentId":"b4730d7f-c54d-4736-8a04-c6203aa2fd49","role":"assigned"},{"agentId":"fe887179-933f-47d4-960f-c3b06827f86c","role":"assigned"}]
 attachments: []
 createdBy: {"kind":"agent","agent_id":"a6c6ea12-bfc6-4bdc-8031-324102dfa34d"}
-updatedBy: {"kind":"agent","agent_id":"a6c6ea12-bfc6-4bdc-8031-324102dfa34d"}
+updatedBy: {"kind":"agent","agent_id":"1ff94b51-3e17-4a39-8543-7715d1ff0f80"}
 createdAt: 1786017501962
-updatedAt: 1786018356463
-version: 3
+updatedAt: 1786024054225
+version: 7
 ---
 Extend the SDK/plugin model so a plugin can contribute commands to the agent custom CLI slash-command system. Product decision: a plugin-contributed command is backed by a callback/function provided by the plugin, so the plugin can decide what the command actually does. Plugin commands must flow through the same unified registry/contract consumed by the frontend, with metadata sufficient for autocomplete and command execution. This ticket is about the extension seam and registration model, not the core native commands or the initial frontend menu.