fix(web): show the full commit hash in the build footer

The footer abbreviated to 7 characters, so the line read
"v master · 19f0319". That line exists to be pasted into `git show` or
compared against a registry tag, and an abbreviation makes both a manual
step — while the full 40-char value was already baked into the image
(build.yml passes `github.sha` whole, and /version returns it untouched).

`shortSha` had no other caller, so it goes with it.

The span gets `overflow-wrap: anywhere` and `min-width: 0`: hex offers no
break opportunity, and the api/web mismatch branch renders two of these
hashes side by side, which would otherwise push a phone into horizontal
scroll. Measured at a simulated 360px with both hashes present — the span
wraps, and documentElement.scrollWidth stays equal to clientWidth.

Verified in the browser against the dev database: footer renders
"v1.0.0 · db2bd54c0ffee1234567890abcdef0123456789a", hash length 40.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

apps/web/src/lib/build-info.ts

@@ -35,8 +35,3 @@ export function webBuildInfo(): BuildInfo {
   const injected = (window as { __APP_BUILD__?: BuildInfo }).__APP_BUILD__;
   return injected ?? UNKNOWN_BUILD;
 }
-
-/** First 7 chars, the length git itself abbreviates to. */
-export function shortSha(sha: string): string {
-  return sha === "unknown" ? sha : sha.slice(0, 7);
-}