fix: Docker hardening, security, and deployment readiness for V1 (#82)

Phase 1 — Docker Artifact Optimization:
- Replace broad `COPY . .` with targeted frontend source copies (API/Python
  changes no longer bust the frontend build cache)
- Replace build-essential with gcc/g++ (leaner runtime)
- Fix LOG_LEVEL=debug → info for production
- Harden .dockerignore (exclude worktrees, IDE, CI, test artifacts)

Phase 2 — State & Persistence:
- Add PUID/PGID support in entrypoint.sh for bind mount compatibility
- Guard against PUID=0/PGID=0 to prevent accidental root execution
- Evict conflicting system users (e.g. node:1000) before UID remap

Phase 3 — Security:
- Always register @fastify/rate-limit so login brute-force protection
  works even when global rate limit is disabled (RATE_LIMIT_PER_MIN=0)
- Add trustProxy support (TRUST_PROXY env var, default true) so rate
  limiting and audit logs use real client IPs behind reverse proxies
- Strip stack traces from 500 error responses in production
- Fix FSTDEP022 deprecation: maxParamLength → routerOptions
- Add multi-file guard on single-file tool endpoint with clear error
  message pointing to the /batch endpoint

Phase 4 — Graceful Degradation:
- Add consolidated hardware detection startup banner (GPU, rate limit,
  upload limit, proxy status)
- Add ConnectionMonitor component with health polling and reconnecting
  overlay that auto-dismisses when the server comes back

Phase 5 — Deployment Docs:
- Rewrite deployment.md with copy-paste CPU and GPU compose templates
- Add hardware requirements table (minimum, recommended, heavy workloads)
- Add PUID/PGID bind mount documentation
- Add complete env var reference table
- Add reverse proxy guides for Nginx, Nginx Proxy Manager, Traefik,
  and Cloudflare Tunnels

apps/api/src/index.ts

@@ -42,7 +42,8 @@ recoverInterruptedInstalls();
 const app = Fastify({
   logger: { level: env.LOG_LEVEL },
   bodyLimit: env.MAX_UPLOAD_SIZE_MB > 0 ? env.MAX_UPLOAD_SIZE_MB * 1024 * 1024 : 1073741824,
-  maxParamLength: 500,
+  trustProxy: env.TRUST_PROXY,
+  routerOptions: { maxParamLength: 500 },
 });
 
 app.setErrorHandler((error: Error & { statusCode?: number }, request, reply) => {
@@ -51,9 +52,11 @@ app.setErrorHandler((error: Error & { statusCode?: number }, request, reply) =>
     { err: error, url: request.url, method: request.method },
     "Unhandled request error",
   );
+  const isProduction = process.env.NODE_ENV === "production";
   reply.status(statusCode).send({
     error: statusCode >= 500 ? "Internal server error" : error.message,
-    details: error.stack ?? error.message,
+    ...(statusCode < 500 && { details: error.message }),
+    ...(!isProduction && statusCode >= 500 && { details: error.stack ?? error.message }),
   });
 });
 
@@ -80,13 +83,14 @@ app.addHook("onSend", async (_request, reply) => {
   }
 });
 
-if (env.RATE_LIMIT_PER_MIN > 0) {
-  await app.register(rateLimit, {
-    max: env.RATE_LIMIT_PER_MIN,
-    timeWindow: "1 minute",
-    allowList: (request) => !request.url.startsWith("/api/"),
-  });
-}
+// Always register rate-limit plugin so per-route limits (login brute-force protection) work.
+// When RATE_LIMIT_PER_MIN=0, the global limit is set high enough to be effectively unlimited
+// while still enabling per-route overrides like the login endpoint.
+await app.register(rateLimit, {
+  max: env.RATE_LIMIT_PER_MIN > 0 ? env.RATE_LIMIT_PER_MIN : 50000,
+  timeWindow: "1 minute",
+  allowList: (request) => !request.url.startsWith("/api/"),
+});
 
 // Multipart upload support
 await registerUpload(app);
@@ -190,7 +194,18 @@ const cleanupCron = startCleanupCron();
 // Start
 try {
   await app.listen({ port: env.PORT, host: "0.0.0.0" });
-  console.log(`ashim API running on port ${env.PORT}`);
+  const gpu = isGpuAvailable();
+  console.log(
+    [
+      `ashim v${APP_VERSION} running on port ${env.PORT}`,
+      gpu
+        ? "[INFO] GPU detected — AI tools will use CUDA acceleration"
+        : "[WARN] No GPU detected — AI tools will use CPU (slower)",
+      `[INFO] Rate limit: ${env.RATE_LIMIT_PER_MIN > 0 ? `${env.RATE_LIMIT_PER_MIN}/min` : "disabled"}`,
+      `[INFO] Upload limit: ${env.MAX_UPLOAD_SIZE_MB > 0 ? `${env.MAX_UPLOAD_SIZE_MB} MB` : "unlimited"}`,
+      `[INFO] Trust proxy: ${env.TRUST_PROXY}`,
+    ].join("\n"),
+  );
 } catch (err) {
   app.log.error(err);
   process.exit(1);

apps/api/src/lib/env.ts

@@ -40,6 +40,10 @@ const envSchema = z.object({
   MAX_PDF_PAGES: z.coerce.number().default(0),
   SESSION_DURATION_HOURS: z.coerce.number().default(168),
   LOGIN_ATTEMPT_LIMIT: z.coerce.number().default(10),
+  TRUST_PROXY: z
+    .enum(["true", "false"])
+    .default("true")
+    .transform((v) => v === "true"),
 });
 
 export type Env = z.infer<typeof envSchema>;

apps/api/src/routes/tool-factory.ts

@@ -110,6 +110,7 @@ export function createToolRoute<T>(app: FastifyInstance, config: ToolRouteConfig
       let filename = "image";
       let settingsRaw: string | null = null;
       let fileId: string | null = null;
+      let fileCount = 0;
 
       // Parse multipart parts
       try {
@@ -117,6 +118,14 @@ export function createToolRoute<T>(app: FastifyInstance, config: ToolRouteConfig
 
         for await (const part of parts) {
           if (part.type === "file") {
+            fileCount++;
+            if (fileCount > 1) {
+              // Drain remaining parts to avoid hanging the connection
+              for await (const _ of part.file) {
+                /* drain */
+              }
+              continue;
+            }
             // Consume the file stream into a buffer
             const chunks: Buffer[] = [];
             for await (const chunk of part.file) {
@@ -141,6 +150,12 @@ export function createToolRoute<T>(app: FastifyInstance, config: ToolRouteConfig
         });
       }
 
+      if (fileCount > 1) {
+        return reply.status(400).send({
+          error: `This endpoint processes one image at a time. Use /api/v1/tools/${config.toolId}/batch for multiple files.`,
+        });
+      }
+
       // Require a file
       if (!fileBuffer || fileBuffer.length === 0) {
         return reply.status(400).send({ error: "No image file provided" });