feat: expand session adapter registry with structured targets

- Registry accepts { type, value } structured targets
- Add --list-adapters and --target-type CLI flags to session-inspect
- Export adapter type from claude-history and dmux-tmux adapters
- 71 new session adapter tests, 34 new session-inspect tests
- All 1142 tests passing

scripts/lib/session-adapters/dmux-tmux.js

@@ -45,6 +45,8 @@ function createDmuxTmuxAdapter(options = {}) {
 
   return {
     id: 'dmux-tmux',
+    description: 'Tmux/worktree orchestration snapshots from plan files or session names',
+    targetTypes: ['plan', 'session'],
     canOpen(target, context = {}) {
       if (context.adapterId && context.adapterId !== 'dmux-tmux') {
         return false;