Fix shell details: distro name, storage path only in footer

- OS name comes from /etc/os-release (e.g. 'CachyOS Linux'), mirroring
  the original app's os_utils; macOS/Windows get proper names too
- Status pill shows the name as-is instead of uppercasing it
- Removed the watched-folder path next to the logo; it now appears only
  in the footer strip (spec updated to match)

frontend/design.md_j621_frontend_spec.md

@@ -77,12 +77,12 @@ All tag chips, counters, and sidebar taxonomy badges strictly adhere to e621's e
 
 ### 4.1 Global Frame (Shell)
 - **Top App Bar (`#11111b`, height: 56px):**
-  - Left: Brand mark `J621` badge (`#cba6f7`) followed by the **storage line** — the path of the watched folder that J621 indexes (e.g. `/mnt/media/library`). J621 is folder-based: this is just a path on disk, not a NAS/appliance indicator.
+  - Left: Brand mark `J621` badge (`#cba6f7`) only. The watched folder path lives in the footer status strip, not in the header.
   - Center: Nav pills: `Library`, `Online`, `Pools`, `Followed`, `Upload`, `Duplicates`, and `Stats [STAFF]`.
   - Right: System status pill with real backend values, never hardcoded: environment (`DEV`/`PROD`), git commit hash, the actual host OS, page generation time, and the total e621 API request time for that page load — e.g. `ENV: PROD · a1b2c3d · LINUX · 18ms (e621: 4ms)`. Followed by the user avatar.
 - **Global Footer Status Strip (`#11111b`, height: 32px):**
   - The strip placement is a proposal; its values are real and drawn from the existing stats data.
-  - Left: the watched folder path — `📁 Local Storage: /mnt/media/library`.
+  - Left: the watched folder path — `📁 Local Storage: /mnt/media/library`. This is the only place the path appears (J621 is folder-based; it is just a path on disk, not a NAS/appliance indicator).
   - Center: `⚡ Active Workers: N running | Queue: M pending` — the count of active optimization/ingest jobs and queued downloads (the original app surfaced this on its stats page; the footer simply keeps it visible).
   - Right: the running build — `<env> @ <git commit hash>` (e.g. `dev @ 3f35330`), matching the original app.
 - **Collapsible Sidebar (Behavior):**

frontend/src/components/AppShell.tsx

@@ -53,15 +53,6 @@ export function AppShell() {
             </span>
           </Link>
 
-          {status ? (
-            <span
-              className="hidden max-w-[240px] truncate font-mono text-[11px] text-ctp-overlay0 md:block"
-              title={status.watched_folder}
-            >
-              {status.watched_folder}
-            </span>
-          ) : null}
-
           {showSidebarToggle ? (
             <button
               type="button"

frontend/src/components/StatusPill.tsx

@@ -34,7 +34,7 @@ export function StatusPill({ status }: { status?: SystemStatus }) {
       <span>{status.git_hash}</span>
       <span className="text-ctp-surface2">·</span>
       <OsIcon className="h-3 w-3" />
-      <span>{status.os.name.toUpperCase()}</span>
+      <span>{status.os.name}</span>
       <span className="text-ctp-surface2">·</span>
       <span>{formatMs(status.server_time_ms)}</span>
       {status.e621_time_ms !== null ? (