chore: switch typecheck from tsgo to tsc, clean up untracked files

- tsgo (experimental @typescript/native-preview) reports 299 false
  positives; standard tsc passes clean. Switch back until tsgo stabilizes.
- Removed untracked src/web/ directory
- Added session-ses_*.md to .gitignore

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

Author: bobbyjohnstx

.gitignore

@@ -34,3 +34,4 @@ tsconfig.tsbuildinfo
 plans/
 .claude/
 .npmrc
+session-ses_*.md

packages/tinycode/package.json

@@ -6,7 +6,7 @@
   "license": "MIT",
   "private": true,
   "scripts": {
-    "typecheck": "tsgo --noEmit",
+    "typecheck": "tsc --noEmit",
     "test": "bun test --timeout 30000",
     "test:ci": "mkdir -p .artifacts/unit && bun test --timeout 30000 --reporter=junit --reporter-outfile=.artifacts/unit/junit.xml",
     "test:httpapi": "bun run script/httpapi-exercise.ts --mode coverage --fail-on-missing --fail-on-skip && bun run script/httpapi-exercise.ts --mode auth --fail-on-missing --fail-on-skip && bun run script/httpapi-exercise.ts --mode effect --fail-on-missing --fail-on-skip",