chore: rename Stirling-Image to ashim across entire codebase

Complete rebrand from Stirling-Image to ashim following the project
move to https://github.com/ashim-hq/ashim.

Changes across 117 files:
- Package scope: @stirling-image/* → @ashim/*
- GitHub URLs: stirling-image/stirling-image → ashim-hq/ashim
- Docker Hub: stirlingimage/stirling-image → ashimhq/ashim
- GitHub Pages: stirling-image.github.io → ashim-hq.github.io
- All branding text: "Stirling Image" → "ashim"
- Docker service/volumes/user: stirling → ashim
- Database: stirling.db → ashim.db
- localStorage keys: stirling-token → ashim-token
- Environment variables: STIRLING_GPU → ASHIM_GPU
- Python cache dirs: .cache/stirling-image → .cache/ashim
- SVG filter IDs, test prefixes, and all other references

apps/web/src/lib/api.ts

@@ -4,7 +4,7 @@ const API_BASE = "/api";
 
 function getToken(): string {
   try {
-    return localStorage.getItem("stirling-token") || "";
+    return localStorage.getItem("ashim-token") || "";
   } catch {
     return "";
   }
@@ -71,11 +71,11 @@ export async function apiDelete<T>(path: string): Promise<T> {
 }
 
 export function setToken(token: string) {
-  localStorage.setItem("stirling-token", token);
+  localStorage.setItem("ashim-token", token);
 }
 
 export function clearToken() {
-  localStorage.removeItem("stirling-token");
+  localStorage.removeItem("ashim-token");
 }
 
 // ── File Upload / Download ──────────────────────────────────────