feat: add Rust reverse proxy with JSON logging

- Axum-based API server with Unix socket and TCP support
- Custom tracing formatters for Railway-compatible JSON logs
- SvelteKit hooks and Vite plugin for unified logging
- Justfile updated for concurrent dev workflow with hl log viewer

web/vite-plugin-json-logger.ts

@@ -0,0 +1,170 @@
+import type { Plugin, ViteDevServer } from "vite";
+import { configure, getLogger, type LogRecord } from "@logtape/logtape";
+
+interface RailwayLogEntry {
+  timestamp: string;
+  level: string;
+  message: string;
+  target: string;
+  [key: string]: unknown;
+}
+
+/**
+ * Railway-compatible JSON formatter for Vite logs
+ */
+function railwayFormatter(record: LogRecord): string {
+  const entry: RailwayLogEntry = {
+    timestamp: new Date().toISOString(),
+    level: record.level.toLowerCase(),
+    message: record.message.join(" "),
+    target: "vite",
+  };
+
+  // Flatten properties to root level
+  if (record.properties && Object.keys(record.properties).length > 0) {
+    Object.assign(entry, record.properties);
+  }
+
+  return JSON.stringify(entry) + "\n";
+}
+
+// Strip ANSI escape codes from strings
+function stripAnsi(str: string): string {
+  return str.replace(/\u001b\[[0-9;]*m/g, "").trim();
+}
+
+export function jsonLogger(): Plugin {
+  const useJsonLogs =
+    process.env.LOG_JSON === "true" || process.env.LOG_JSON === "1";
+
+  // If JSON logging is disabled, return a minimal plugin that does nothing
+  if (!useJsonLogs) {
+    return {
+      name: "vite-plugin-json-logger",
+    };
+  }
+
+  // Configure LogTape for Vite plugin logging
+  let loggerConfigured = false;
+  const configureLogger = async () => {
+    if (loggerConfigured) return;
+    await configure({
+      sinks: {
+        json: (record: LogRecord) => {
+          process.stdout.write(railwayFormatter(record));
+        },
+      },
+      filters: {},
+      loggers: [
+        // Suppress LogTape meta logger info messages
+        {
+          category: ["logtape", "meta"],
+          lowestLevel: "warning",
+          sinks: ["json"],
+        },
+        {
+          category: ["vite"],
+          lowestLevel: "debug",
+          sinks: ["json"],
+        },
+      ],
+    });
+    loggerConfigured = true;
+  };
+
+  let server: ViteDevServer;
+  const ignoredMessages = new Set(["press h + enter to show help", "ready in"]);
+
+  return {
+    name: "vite-plugin-json-logger",
+
+    async config() {
+      await configureLogger();
+      const logger = getLogger(["vite"]);
+
+      return {
+        customLogger: {
+          info(msg: string) {
+            const cleaned = stripAnsi(msg);
+            // Filter out noise
+            if (
+              !cleaned ||
+              ignoredMessages.has(cleaned) ||
+              cleaned.includes("VITE v")
+            ) {
+              return;
+            }
+            logger.info(cleaned);
+          },
+          warn(msg: string) {
+            const cleaned = stripAnsi(msg);
+            if (cleaned) {
+              logger.warn(cleaned);
+            }
+          },
+          error(msg: string) {
+            const cleaned = stripAnsi(msg);
+            if (cleaned) {
+              logger.error(cleaned);
+            }
+          },
+          clearScreen() {
+            // No-op since clearScreen is already false
+          },
+          hasErrorLogged() {
+            return false;
+          },
+          hasWarned: false,
+          warnOnce(msg: string) {
+            this.warn(msg);
+          },
+        },
+      };
+    },
+
+    configureServer(s) {
+      server = s;
+      const logger = getLogger(["vite"]);
+
+      // Override the default URL printing
+      const originalPrintUrls = server.printUrls;
+      server.printUrls = () => {
+        const urls = server.resolvedUrls;
+        if (urls) {
+          logger.info("dev server running", {
+            local: urls.local,
+            network: urls.network,
+          });
+        }
+      };
+
+      // Listen to server events
+      server.httpServer?.once("listening", () => {
+        logger.info("server listening");
+      });
+
+      server.ws.on("connection", () => {
+        logger.info("client connected");
+      });
+    },
+
+    handleHotUpdate({ file, modules }) {
+      const logger = getLogger(["vite"]);
+      logger.info("hmr update", {
+        file: file.replace(process.cwd(), ""),
+        modules: modules.length,
+      });
+      return modules;
+    },
+
+    buildStart() {
+      const logger = getLogger(["vite"]);
+      logger.info("build started");
+    },
+
+    buildEnd() {
+      const logger = getLogger(["vite"]);
+      logger.info("build ended");
+    },
+  };
+}