Add tm_server with SQLite, Svelte UI, and task-master TUI sync.

Introduces the web backend (auth, RBAC, project tokens, revisions),
YouTrack-or-taskmaster backend choice in the TUI, and a first-pass
embedded Svelte UI. The frontend is functional but needs a major rework.

Co-authored-by: Cursor <cursoragent@cursor.com>

.gitignore

@@ -6,3 +6,8 @@
 # Generated by `make demo` / CI — commit demo.gif so the README preview works on Gitea
 demo.mp4
 demo.webm
+web/node_modules/
+web/dist/
+*.db
+*.db-wal
+*.db-shm