feat: add update_resume_synced_at and update_resume_content db helpers

Expose synced_at in _resume_as_dict (with safe fallback for pre-migration
DBs), and add two new helpers: update_resume_synced_at (library→profile
direction) and update_resume_content (profile→library direction, updates
text/struct_json/word_count/synced_at/updated_at).

scripts/db.py

@@ -973,6 +973,7 @@ def _resume_as_dict(row) -> dict:
         "is_default":  row["is_default"],
         "created_at":  row["created_at"],
         "updated_at":  row["updated_at"],
+        "synced_at":   row["synced_at"] if "synced_at" in row.keys() else None,
     }
 
 
@@ -1074,6 +1075,44 @@ def set_default_resume(db_path: Path = DEFAULT_DB, resume_id: int = 0) -> None:
         conn.close()
 
 
+def update_resume_synced_at(db_path: Path = DEFAULT_DB, resume_id: int = 0) -> None:
+    """Mark a library entry as synced to the profile (library→profile direction)."""
+    conn = sqlite3.connect(db_path)
+    try:
+        conn.execute(
+            "UPDATE resumes SET synced_at=datetime('now') WHERE id=?",
+            (resume_id,),
+        )
+        conn.commit()
+    finally:
+        conn.close()
+
+
+def update_resume_content(
+    db_path: Path = DEFAULT_DB,
+    resume_id: int = 0,
+    text: str = "",
+    struct_json: str | None = None,
+) -> None:
+    """Update text, struct_json, and synced_at for a library entry.
+
+    Called by the profile→library sync path (PUT /api/settings/resume).
+    """
+    word_count = len(text.split()) if text else 0
+    conn = sqlite3.connect(db_path)
+    try:
+        conn.execute(
+            """UPDATE resumes
+               SET text=?, struct_json=?, word_count=?,
+                   synced_at=datetime('now'), updated_at=datetime('now')
+               WHERE id=?""",
+            (text, struct_json, word_count, resume_id),
+        )
+        conn.commit()
+    finally:
+        conn.close()
+
+
 def get_job_resume(db_path: Path = DEFAULT_DB, job_id: int = 0) -> dict | None:
     """Return the resume for a job: job-specific first, then default, then None."""
     conn = sqlite3.connect(db_path)