fix(mcp): pass ingest flag through service CLI

Ensure mcp_service.sh start --enable-ingest actually writes OBSIDIAN_MCP_ENABLE_INGEST=1 by forwarding the parsed flag to start_service.

Also stop the new-token command from referencing the start-only flag, and cover both CLI paths with regression tests.

Validation: python3 -m unittest discover -v; git diff --check

scripts/manage_mcp_service.py

@@ -406,7 +406,6 @@ def main(argv: Sequence[str] | None = None) -> int:
                 port=args.port,
                 path=args.path,
                 token_bytes=args.token_bytes,
-                enable_ingest=args.enable_ingest,
             ),
             end="",
         )
@@ -420,6 +419,7 @@ def main(argv: Sequence[str] | None = None) -> int:
                 port=args.port,
                 path=args.path,
                 token_bytes=args.token_bytes,
+                enable_ingest=args.enable_ingest,
             ),
             end="",
         )