fix: backfill symbol_demand for sidebar-added symbols + analyst ratings schema fix

- Add await ctx.cache.subscribe() to addSymbol mutation so symbols
  added via the sidebar get registered in symbol_demand and yfinance
  jobs are queued immediately
- Backfill PEP, WYNN, STZ, CELH into symbol_demand + adapter_queue
- Upgrade yahoo-finance2 3.15.3 -> 3.15.4 and pass validateResult:false
  to quoteSummary() to handle Yahoo schema drift
- Add error detail logging for analyst ratings schema failures
- Update .gitignore with common ignores

.gitignore

@@ -7,3 +7,21 @@
 .lancedb/
 .obsidian/workspace*.json
 .sessions/
+
+# Dependencies
+node_modules/
+.next/
+.next
+
+# Agent scratch
+.scratch/
+Agent/
+.design/
+
+# Lavish reports
+.lavish/
+
+# Design docs
+design/
+
+