Rename to stealergram, add pyproject.toml, purge em-dashes

- Rename project to stealergram throughout
- Add pyproject.toml (replaces requirements.txt split, folds pytest.ini)
- Replace all em-dashes with hyphens across all source files

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/db.py

@@ -1,9 +1,9 @@
 """
-web/db.py — SQLite user store for the web frontend.
+web/db.py - SQLite user store for the web frontend.
 
 Tables:
-  users          — credentials + role + active flag
-  refresh_tokens — JTI-indexed refresh token revocation list
+  users - credentials + role + active flag
+  refresh_tokens - JTI-indexed refresh token revocation list
 
 Bootstrap: on first init, creates a superadmin from WEB_ADMIN_USER / WEB_ADMIN_PASS
 env vars (required only on first run if the DB doesn't exist yet).
@@ -63,7 +63,9 @@ def init_db() -> None:
             admin_pass = os.environ.get("WEB_ADMIN_PASS")
             if not admin_pass:
                 raise RuntimeError(
-                    "WEB_ADMIN_PASS env var is required on first run to create the superadmin."
+                    "WEB_ADMIN_PASS env var is required on first run to bootstrap the superadmin. "
+                    "Add WEB_ADMIN_PASS=<password> (and optionally WEB_ADMIN_USER=<username>) "
+                    "to your .env file, then restart."
                 )
             conn.execute(
                 "INSERT INTO users (id, username, password_hash, role, created_at) VALUES (?,?,?,?,?)",