chore(budget): re-baseline aggregate Rust ceiling for session-title fix

Session-title fix (f04e1b7) plus the portable-evidence test grew
owned Rust 673375 -> 673417 (+42 lines): two regression tests, the
DEFAULT_SESSION_TITLE constant, and comments. Regression tests are
durable assets, not overspend to pay down. No new modules.

Author: SparkofSpike

scripts/source-structure-budget.json

@@ -186,11 +186,12 @@
     "codewhale-tui:codewhale-tui"
   ],
   "_todo_2026_08_06_windows_lane": "v0.9.4 Windows/no-sandbox test-lane repair: aggregate 673296 -> 673375 (+79 lines). The 12 failures blocking the ship were not Windows-only - 7 fail on any host with no OS sandbox backend (all Windows, Linux without bubblewrap), and release.yml's parity job runs the full suite on ubuntu-latest, so the tag itself would have failed. Growth is a pinned sandbox backend in the underwater test fixture plus one new test covering the unenforced rendering the fixture no longer exercises, the rooted-mention and native-separator fixes in file_mention, and their comments. No new modules; growth is in existing files. Pay down in v0.9.5.",
+  "_todo_2026_08_07_session_title_fix": "Session title pinned at New Session fix (codex/session-title-fix): aggregate 673375 -> 673417 (+42 lines). Growth is the two regression tests for the title-resolution priority rules (stale cached placeholder, persisted placeholder healing) plus the DEFAULT_SESSION_TITLE constant and its comments — regression tests are durable assets, not overspend to pay down. No new modules; growth is in existing files.",
   "document_kind": "codewhale.source_structure_budget",
   "large_module_threshold_lines": 1000,
   "max_large_module_count": 175,
   "max_module_lines": 17596,
-  "max_total_owned_rust_lines": 673375,
+  "max_total_owned_rust_lines": 673417,
   "schema_version": 1,
   "workspace_packages": [
     "codewhale-agent",