fix: resolve all 301 error handling anti-patterns across codebase

Systematic cleanup of every error handling anti-pattern detected by the
automated scanner. 289 issues fixed via code changes, 12 approved with
specific technical justifications.

Changes across 90 files:
- GENERIC_CATCH (141): Added instanceof Error type discrimination
- LARGE_TRY_BLOCK (82): Extracted helper methods to narrow try scope to ≤10 lines
- NO_LOGGING_IN_CATCH (65): Added logger/console calls for error visibility
- CATCH_AND_CONTINUE_CRITICAL_PATH (10): Added throw/return or approved overrides
- ERROR_STRING_MATCHING (2): Approved with rationale (no typed error classes)
- ERROR_MESSAGE_GUESSING (1): Replaced chained .includes() with documented pattern array
- PROMISE_CATCH_NO_LOGGING (1): Added logging to .catch() handler

Also fixes a detector bug where nested try/catch inside a catch block
corrupted brace-depth tracking, causing false positives.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/shared/timeline-formatting.ts

@@ -16,10 +16,10 @@ export function parseJsonArray(json: string | null): string[] {
   try {
     const parsed = JSON.parse(json);
     return Array.isArray(parsed) ? parsed : [];
-  } catch (err) {
+  } catch (err: unknown) {
     logger.debug('PARSER', 'Failed to parse JSON array, using empty fallback', {
       preview: json?.substring(0, 50)
-    }, err as Error);
+    }, err instanceof Error ? err : new Error(String(err)));
     return [];
   }
 }