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/api/src/index.ts

@@ -23,14 +23,6 @@ import { teamsRoutes } from "./routes/teams.js";
 import { registerToolRoutes } from "./routes/tools/index.js";
 import { userFileRoutes } from "./routes/user-files.js";
 
-// Warn about deprecated STIRLING_VARIANT env var
-if (process.env.STIRLING_VARIANT) {
-  console.warn(
-    `WARNING: STIRLING_VARIANT="${process.env.STIRLING_VARIANT}" is set but ignored. ` +
-      "There is now a single unified image with all features. Remove STIRLING_VARIANT from your environment.",
-  );
-}
-
 // Run before anything else
 runMigrations();
 console.log("Database initialized");

apps/api/src/routes/settings.ts

@@ -6,7 +6,6 @@
  * GET  /api/v1/settings/:key — Get a specific setting
  */
 
-import { PYTHON_SIDECAR_TOOLS } from "@stirling-image/shared";
 import { eq } from "drizzle-orm";
 import type { FastifyInstance, FastifyReply, FastifyRequest } from "fastify";
 import { db, schema } from "../db/index.js";
@@ -27,10 +26,7 @@ export async function settingsRoutes(app: FastifyInstance): Promise<void> {
       settings[row.key] = row.value;
     }
 
-    const variant = process.env.STIRLING_VARIANT === "lite" ? "lite" : "full";
-    const variantUnavailableTools = variant === "lite" ? [...PYTHON_SIDECAR_TOOLS] : [];
-
-    return reply.send({ settings, variant, variantUnavailableTools });
+    return reply.send({ settings });
   });
 
   // PUT /api/v1/settings — Save settings (admin only)

apps/api/src/routes/tools/index.ts

@@ -1,4 +1,4 @@
-import { PYTHON_SIDECAR_TOOLS, TOOLS } from "@stirling-image/shared";
+import { TOOLS } from "@stirling-image/shared";
 import { eq } from "drizzle-orm";
 import type { FastifyInstance } from "fastify";
 import { db, schema } from "../../db/index.js";
@@ -69,10 +69,6 @@ export async function registerToolRoutes(app: FastifyInstance): Promise<void> {
   // Build skip set
   const skipTools = new Set([...disabledTools, ...(enableExperimental ? [] : experimentalToolIds)]);
 
-  // In lite mode, register 501 stubs for AI tools instead of real handlers
-  const isLite = process.env.STIRLING_VARIANT === "lite";
-  const liteStubTools = new Set<string>(PYTHON_SIDECAR_TOOLS);
-
   const toolRegistrations: Array<{
     id: string;
     register: (app: FastifyInstance) => void;
@@ -131,7 +127,6 @@ export async function registerToolRoutes(app: FastifyInstance): Promise<void> {
   ];
 
   let skipped = 0;
-  let stubbed = 0;
   for (const { id, register } of toolRegistrations) {
     if (skipTools.has(id)) {
       app.log.info(`Skipping disabled/experimental tool: ${id}`);
@@ -139,24 +134,11 @@ export async function registerToolRoutes(app: FastifyInstance): Promise<void> {
       continue;
     }
 
-    if (isLite && liteStubTools.has(id)) {
-      // Register a 501 stub instead of the real handler
-      app.post(`/api/v1/tools/${id}`, async (_request, reply) => {
-        return reply.status(501).send({
-          statusCode: 501,
-          error: "Not Available",
-          message: `The "${id}" tool requires the full image. Pull stirlingimage/stirling-image:latest for all features.`,
-        });
-      });
-      stubbed++;
-      continue;
-    }
-
     register(app);
   }
 
-  const registered = toolRegistrations.length - skipped - stubbed;
+  const registered = toolRegistrations.length - skipped;
   app.log.info(
-    `Tool routes: ${registered} active, ${stubbed} lite-stubbed, ${skipped} skipped (${toolRegistrations.length} total)`,
+    `Tool routes: ${registered} active, ${skipped} skipped (${toolRegistrations.length} total)`,
   );
 }