fix(activity-feed): remove [:120] slug truncation

Claim slugs were being cut at 120 chars in _extract_claim_slugs, causing
Timeline event clicks to 404 when the on-disk filename exceeded that
length (frontend builds /api/claims/<slug> from the truncated value).

This fix landed Apr 26 but regressed when the file was redeployed —
committing the unmangled version to repo so deploy.sh re-shipping
doesn't reintroduce the cap.

Verified live: max slug now 265 chars, 16 of 30 over the old 120 cap.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

diagnostics/activity_feed_api.py

@@ -102,7 +102,7 @@ def _extract_claim_slugs(description, branch=None):
         if branch:
             parts = branch.split("/", 1)
             if len(parts) > 1:
-                return [parts[1][:120]]
+                return [parts[1]]
         return []
     titles = [t.strip() for t in description.split("|") if t.strip()]
     slugs = []
@@ -111,7 +111,7 @@ def _extract_claim_slugs(description, branch=None):
         slug = "".join(c if c.isalnum() or c in (" ", "-") else "" for c in slug)
         slug = slug.replace(" ", "-").strip("-")
         if len(slug) > 10:
-            slugs.append(slug[:120])
+            slugs.append(slug)
     return slugs