Phase 5: alert subscriptions UI + multiple watchlists + queue fixes

UI:
- /alerts page: event history with acknowledge, subscription create/manage with toggle
- /admin/smtp: SMTP config form (host, port, auth, test)
- Watchlist sidebar: dropdown selector for multiple watchlists, create/delete
- Sidebar: alerts count badge, SMTP link under admin
- Mobile tab nav: alerts tab added
- Client trpc.ts: all new API methods + types

Backend:
- watchlists.listByWatchlist procedure + listSymbolsByWatchlist repo fn
- yfinance min-interval 1500->2000ms to reduce Edge 429s
- Fixed e.date.slice error in yfinance-adjustments with typeof guard
- Removed defunct BITF from watchlist+queue
- Cleared 83 failed + 12 backoff queue jobs

Docs:
- FUNCTIONAL_DESIGN.md: alerts + multiple watchlists + SMTP documented
- TECH_DESIGN.md: new modules, tRPC procs, routes updated

app/server/package-lock.json

@@ -9,11 +9,13 @@
       "version": "0.1.0",
       "dependencies": {
         "@trpc/server": "^11.0.0",
+        "nodemailer": "^9.0.3",
         "yahoo-finance2": "^3.15.4",
         "zod": "^4.4.3"
       },
       "devDependencies": {
         "@types/node": "^22.0.0",
+        "@types/nodemailer": "^8.0.1",
         "typescript": "^5.0.0"
       },
       "engines": {
@@ -113,6 +115,16 @@
         "undici-types": "~6.21.0"
       }
     },
+    "node_modules/@types/nodemailer": {
+      "version": "8.0.1",
+      "resolved": "https://registry.npmjs.org/@types/nodemailer/-/nodemailer-8.0.1.tgz",
+      "integrity": "sha512-PxpaInm8V1JQDd4j0ds5HfvWQk8JupS1C0Picb96QJsrrRDjBH+DlK7L4ZdNSqNULhiZRQHc40nLVShaGxXAMw==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@types/node": "*"
+      }
+    },
     "node_modules/accepts": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/accepts/-/accepts-2.0.0.tgz",
@@ -905,6 +917,15 @@
         "node": ">= 0.6"
       }
     },
+    "node_modules/nodemailer": {
+      "version": "9.0.3",
+      "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-9.0.3.tgz",
+      "integrity": "sha512-n+YP+NKwR5zRWa60k3GiQ6Q3B4KXCoAw40dAKeCtYn020iNN74aWK2liXIC3ZEATeGql7we3tE3t8QwhY0eskw==",
+      "license": "MIT-0",
+      "engines": {
+        "node": ">=6.0.0"
+      }
+    },
     "node_modules/normalize-url": {
       "version": "4.5.1",
       "resolved": "https://registry.npmjs.org/normalize-url/-/normalize-url-4.5.1.tgz",