chore: initialize repository baseline

Import the existing Electron + React + TypeScript app as the version-control
baseline before the scanner rework (C# input/capture sidecar, resolution-anchored
layout profiles, OCR preprocessing, eval harness, rescan-merge, GOOD interop).

Housekeeping in this commit:
- Remove orphaned temp_inputhelper_block.ts (duplicate of the input-helper script).
- Ignore .claude/scheduled_tasks.lock local session state.
- Add .gitattributes to normalize line endings (LF in repo).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,31 @@
+# Dependencies
+node_modules/
+
+# Builds
+dist/
+dist-electron/
+outputs/dist/
+
+# Logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+
+# Local runtime data
+*.local
+.env
+.env.*
+
+# OS/editor
+.DS_Store
+Thumbs.db
+.idea/
+.vscode/
+
+# Temporary work
+work/
+
+# Local session/runtime state
+.claude/scheduled_tasks.lock