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>

docs/branching.md

@@ -0,0 +1,10 @@
+# Branching
+
+This project is currently developed locally. When it becomes a Git repository, use focused branches:
+
+- `feature/<short-name>` for new user-facing features.
+- `fix/<short-name>` for bug fixes.
+- `docs/<short-name>` for documentation-only work.
+- `scanner/<short-name>` for capture, OCR, crop, or parser work.
+
+Keep branches small enough to review and validate quickly.