fix(audit): address /code-review findings

- scheduler _run_changed: count a run as "changed" only on a truthy NUMERIC
  value — status-string no-op dicts like {"skipped":"disabled"} (Plex off, the
  default) or {"skipped":"no demo account"} were flooding the trail every interval.
- audit.record: truncate target_id to the column width (128) like summary[:255],
  so an over-long target (e.g. a 128+ char demo email) can't abort the mutation
  the audit row is committed alongside.
- config set/reset: redact URL userinfo (user:pass@) from logged non-secret
  values — a proxy setting can embed credentials that shouldn't land in the trail.
- config set: skip the audit row when a non-secret value didn't actually change
  (no-op re-save shouldn't add noise); secrets are write-only so always logged.
- audit page title (pageMeta): add the missing "audit" case so the browser tab
  reads "Audit log · Siftlode" instead of falling back to "Feed".

backend/app/routes/config.py

@@ -1,5 +1,7 @@
 """Admin Configuration page API: read/edit the DB-overridable operational settings defined in
 app.sysconfig. Secret values (e.g. SMTP password) are write-only — never returned."""
+import re
+
 from fastapi import APIRouter, Depends, HTTPException
 from sqlalchemy.orm import Session
 
@@ -13,6 +15,15 @@ from app.routes.admin import admin_user
 
 router = APIRouter(prefix="/api/admin/config", tags=["admin"])
 
+# Strip URL userinfo (user:pass@) so a non-secret setting that happens to embed credentials —
+# e.g. an authenticated egress proxy http://user:pass@host:port — never lands plaintext in the
+# audit trail. Non-secret values are shown live in the UI, but the log shouldn't retain creds.
+_URL_USERINFO = re.compile(r"(://)[^/@\s]+@")
+
+
+def _redact(v):
+    return _URL_USERINFO.sub(r"\1***@", v) if isinstance(v, str) else v
+
 
 @router.get("")
 def get_config(_: User = Depends(admin_user), db: Session = Depends(get_db)) -> dict:
@@ -41,15 +52,19 @@ def set_config(
         sysconfig.set_value(db, key, payload["value"])
     except (TypeError, ValueError) as exc:
         raise HTTPException(status_code=400, detail=str(exc) or "Invalid value")
-    # Never log a secret's value — only that it was changed, by whom.
+    # Never log a secret's value — only that it was changed, by whom. Non-secret values are logged
+    # but with URL credentials redacted (a proxy/URL setting can embed user:pass). Skip the row when
+    # a non-secret value didn't actually change (a no-op re-save shouldn't add trail noise); secrets
+    # are write-only so we can't compare — always log.
     new = None if s.secret else sysconfig.get(db, key)
-    audit.record(
-        db, admin.id, AuditAction.CONFIG_SET, target_type="config", target_id=key,
-        summary=f"{key} = (secret updated)" if s.secret else f"{key} = {new}",
-        before=None if s.secret else {"value": old},
-        after=None if s.secret else {"value": new},
-    )
-    db.commit()
+    if s.secret or new != old:
+        audit.record(
+            db, admin.id, AuditAction.CONFIG_SET, target_type="config", target_id=key,
+            summary=f"{key} = (secret updated)" if s.secret else f"{key} = {_redact(new)}",
+            before=None if s.secret else {"value": _redact(old)},
+            after=None if s.secret else {"value": _redact(new)},
+        )
+        db.commit()
     return sysconfig.describe(db)
 
 
@@ -67,7 +82,7 @@ def reset_config(
     audit.record(
         db, admin.id, AuditAction.CONFIG_RESET, target_type="config", target_id=key,
         summary=f"{key} → default",
-        before=None if s.secret else {"value": old},
+        before=None if s.secret else {"value": _redact(old)},
     )
     db.commit()
     return sysconfig.describe(db)