fix: wrap GameOverScreen in ErrorBoundary and add defensive checks for day 30 blank page bug

- Wrap GameOverScreen in ErrorBoundary in page.tsx to prevent blank page on render errors
- Add defensive Number.isFinite checks in GameOverScreen for all numeric props
- Add regression test for day 30 → game-over flow (day30-blank-page.test.ts)

Fixes #375

docs/circular-deps.txt

@@ -1,5 +1,5 @@
 # Circular Dependencies
-Generated: 2026-06-11T10:43:50.823Z
+Generated: 2026-06-11T14:10:00.590Z
 Found: 4 circular chain(s) — these MUST be fixed before modifying involved files.
 
 1. 1) data/guardian-encounters.ts > data/guardian-procedural.ts

docs/dependency-graph.json

@@ -1,6 +1,6 @@
 {
   "_meta": {
-    "generated": "2026-06-11T10:43:48.464Z",
+    "generated": "2026-06-11T14:09:58.499Z",
     "description": "Import dependency graph for src/lib/game. Keys are files, values are arrays of files they import.",
     "usage": "To find what a file affects, search for its path in the VALUES. To find what a file depends on, look at its KEY entry."
   },

docs/project-structure.txt

@@ -217,6 +217,7 @@ Mana-Loop/
 │   │   │   │   ├── cross-module-lifecycle-consistency.test.ts
 │   │   │   │   ├── cross-module-prestige-discipline.test.ts
 │   │   │   │   ├── curse-amplification.test.ts
+│   │   │   │   ├── day30-blank-page.test.ts
 │   │   │   │   ├── design-validation-perk-gating.test.ts
 │   │   │   │   ├── discipline-deactivate-on-spire-entry.test.ts
 │   │   │   │   ├── discipline-math.test.ts