Store optimized dist/ via Git LFS

[epatey]

Note

Based on #290 not main. Most of the changes are from that branch.

Summary

• Move dist/ to Git LFS — minified, tree-shaken, content-hashed build output is now committed as LFS pointer files (~130 bytes each) instead of full blobs, eliminating repo bloat from opaque minified diffs
• Add transparent LFS fallback (_view/_lfs/) — when a user clones without Git LFS installed, scout view detects pointer files at startup and downloads real assets from GitHub's LFS batch API into a local cache (~/.cache/inspect_scout/dist/), so the working tree is never modified
• Enable asset fingerprinting — Vite now produces content-hashed filenames ([name]-[hash].js), allowing proper browser caching and removing the NoCacheStaticFiles workaround
• Add scripts/fetch-dist.sh escape-hatch script for manual LFS object download outside scout view
• Update CI workflows to handle LFS

Design

See design/plans/minified-via-lfs.md

[jjallaire]

Note that the VS Code extension attempts to read the JS directly from the dist path in the repo (it doesn't get it over http) so we'll need to make sure to update it to be able to find these).