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>

internal/sqlite/migrations/002_project_tokens.sql

@@ -0,0 +1,13 @@
+CREATE TABLE IF NOT EXISTS project_tokens (
+  id          TEXT PRIMARY KEY,
+  project_id  TEXT NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
+  name        TEXT NOT NULL,
+  token_hash  TEXT NOT NULL UNIQUE,
+  scope       TEXT NOT NULL,
+  created_by  TEXT REFERENCES users(id) ON DELETE SET NULL,
+  created_at  TEXT NOT NULL,
+  revoked_at  TEXT
+);
+
+CREATE INDEX IF NOT EXISTS idx_project_tokens_project ON project_tokens(project_id);
+CREATE INDEX IF NOT EXISTS idx_project_tokens_hash ON project_tokens(token_hash);