fix(ci): generate route tree before typecheck + enforce LF line endings

Two CI gaps surfaced on first push:

1. typecheck failed because tsc -b ran before vite build, but
   src/routeTree.gen.ts is only generated by the Vite plugin during
   build. tsc has nothing to typecheck against.

   Fix: install @tanstack/router-cli and chain `tsr generate` before
   tsc in the typecheck and build scripts. Now any environment that
   runs typecheck cold (CI, fresh clone) generates the route tree
   first.

   Also added a top-level `route-tree` script so the same command is
   reusable elsewhere if needed.

2. format:check would fail on Windows working trees because
   git autocrlf (default on Windows) checks files out with CRLF, but
   .prettierrc pins endOfLine: "lf". Locally the format:check
   intermittently passed/failed depending on whether files had been
   recently auto-formatted.

   Fix: .gitattributes with `* text=auto eol=lf` enforces LF in every
   working tree. Plus explicit overrides for binary blobs (images) and
   the route tree file. `git add --renormalize .` brought the index in
   line with the new policy; no actual file content changed.

CI on the next push should now see the same green gates the local
working tree shows.

.gitattributes

@@ -0,0 +1,19 @@
+# Enforce LF line endings on every platform.
+# Without this, Windows + git autocrlf (default) checks files out with
+# CRLF, which conflicts with Prettier's `endOfLine: "lf"` and breaks
+# format:check on Windows working trees.
+* text=auto eol=lf
+
+# Generated route tree (gitignored anyway, but if it ever sneaks in)
+src/routeTree.gen.ts text eol=lf
+
+# Lock files: keep LF
+pnpm-lock.yaml text eol=lf
+
+# Binary blobs
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.svg text eol=lf