refactor: remove lite variant, fix release workflow

- Remove all lite/full variant logic from frontend, API, shared constants,
  docs, and tests (single unified Docker image only)
- Replace single QEMU multi-arch Docker build with per-architecture native
  builds (amd64 + arm64) and manifest merge to fix disk space exhaustion
- Add disk cleanup step and per-platform build cache scopes
- Switch release trigger from push to workflow_dispatch
- Add GitHub issue templates and PR template

apps/web/src/components/layout/tool-panel.tsx

@@ -1,5 +1,4 @@
 import { CATEGORIES, TOOLS } from "@stirling-image/shared";
-import { Info } from "lucide-react";
 import { useEffect, useMemo, useState } from "react";
 import { useSettingsStore } from "@/stores/settings-store";
 import { SearchBar } from "../common/search-bar";
@@ -7,15 +6,12 @@ import { ToolCard } from "../common/tool-card";
 
 export function ToolPanel() {
   const [search, setSearch] = useState("");
-  const { variant, disabledTools, experimentalEnabled, variantUnavailableTools, loaded, fetch } =
-    useSettingsStore();
+  const { disabledTools, experimentalEnabled, loaded, fetch } = useSettingsStore();
 
   useEffect(() => {
     fetch();
   }, [fetch]);
 
-  const unavailableSet = useMemo(() => new Set(variantUnavailableTools), [variantUnavailableTools]);
-
   const visibleTools = useMemo(() => {
     if (!loaded) return [];
     return TOOLS.filter((t) => {
@@ -49,27 +45,6 @@ export function ToolPanel() {
         <SearchBar value={search} onChange={setSearch} />
       </div>
       <div className="px-3 pb-4 flex-1">
-        {variant === "lite" && (
-          <div className="mb-3 p-2.5 rounded-lg bg-amber-50 dark:bg-amber-950/30 border border-amber-200 dark:border-amber-800 text-amber-800 dark:text-amber-300">
-            <div className="flex items-start gap-2">
-              <Info className="h-4 w-4 mt-0.5 shrink-0" />
-              <div className="text-xs leading-relaxed">
-                <p className="font-medium">Lite mode</p>
-                <p className="mt-0.5 text-amber-700 dark:text-amber-400">
-                  AI tools are unavailable. Use the{" "}
-                  <code className="font-mono text-[10px] bg-amber-100 dark:bg-amber-900/50 px-1 py-0.5 rounded">
-                    latest
-                  </code>{" "}
-                  or{" "}
-                  <code className="font-mono text-[10px] bg-amber-100 dark:bg-amber-900/50 px-1 py-0.5 rounded">
-                    full
-                  </code>{" "}
-                  tag for all features.
-                </p>
-              </div>
-            </div>
-          </div>
-        )}
         {CATEGORIES.filter((cat) => groupedTools.has(cat.id)).map((category) => (
           <div key={category.id} className="mb-4">
             <h3 className="text-xs font-semibold uppercase text-muted-foreground tracking-wider mb-2">
@@ -77,11 +52,7 @@ export function ToolPanel() {
             </h3>
             <div className="space-y-0.5">
               {groupedTools.get(category.id)?.map((tool) => (
-                <ToolCard
-                  key={tool.id}
-                  tool={tool}
-                  variantUnavailable={unavailableSet.has(tool.id)}
-                />
+                <ToolCard key={tool.id} tool={tool} />
               ))}
             </div>
           </div>