diff --git a/packages/server/src/tools.ts b/packages/server/src/tools.ts
index 8b7a6ed..bf95a91 100644
--- a/packages/server/src/tools.ts
+++ b/packages/server/src/tools.ts
@@ -1,29 +1,18 @@
-/**
- * P0 Core Tool Implementations
- * 
- * file_list, file_read, file_write, file_move, exec, process_list, sysinfo.
- * These map to C-002 through C-011 in the backlog.
- */
-
 import * as fs from "node:fs";
 import * as path from "node:path";
 import { execSync } from "node:child_process";
 import * as os from "node:os";
 
-/** Sandbox: restrict file ops to this base directory or env GCA_WORKSPACE */
 const BASE_DIR = path.resolve(process.env.GCA_WORKSPACE ?? process.cwd());
 
 function safePath(p: string): string {
-  const resolved = path.resolve(BASE_DIR, p);
-  if (!resolved.startsWith(BASE_DIR)) throw new Error(`Path traversal blocked: ${p}`);
-  return resolved;
+  const r = path.resolve(BASE_DIR, p);
+  if (!r.startsWith(BASE_DIR)) throw new Error(`Path traversal blocked: ${p}`);
+  return r;
 }
 
-// 鈹€鈹€ C-002: file_list 鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€
-export async function file_list(args: {
-  path: string;
-  recursive?: boolean;
-}): Promise<any> {
+// ── C-002: file_list ────────────────────────────────────────
+export async function file_list(args: { path: string; recursive?: boolean }): Promise<any> {
   const dir = safePath(args.path || ".");
   const entries = fs.readdirSync(dir, { withFileTypes: true });
   const result = entries.map(e => ({
@@ -34,78 +23,55 @@ export async function file_list(args: {
   return { path: dir, entries: result, count: result.length };
 }
 
-// 鈹€鈹€ C-003: file_read 鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€
-export async function file_read(args: {
-  path: string;
-  encoding?: string;
-  offset?: number;
-  limit?: number;
-}): Promise<any> {
-  const encoding = (args.encoding === "base64" ? "base64" : "utf8") as BufferEncoding;
-  let content = fs.readFileSync(safePath(args.path, encoding);
-  if (encoding === "utf8") {
+// ── C-003: file_read ────────────────────────────────────────
+export async function file_read(args: { path: string; encoding?: string; offset?: number; limit?: number }): Promise<any> {
+  const filePath = safePath(args.path);
+  const enc = (args.encoding === "base64" ? "base64" : "utf8") as BufferEncoding;
+  let content = fs.readFileSync(filePath, enc);
+  if (enc === "utf8") {
     const lines = (content as string).split("\n");
-    const start = args.offset ?? 0;
-    const end = args.limit ? start + args.limit : lines.length;
-    content = lines.slice(start, end).join("\n");
+    content = lines.slice(args.offset ?? 0, args.limit ? (args.offset ?? 0) + args.limit : undefined).join("\n");
   }
-  return { path: args.path, content, size: fs.statSync(safePath(args.path).size };
+  return { path: filePath, content, size: fs.statSync(filePath).size };
 }
 
-// 鈹€鈹€ C-004: file_write 鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€
-export async function file_write(args: {
-  path: string;
-  content: string;
-  encoding?: string;
-}): Promise<any> {
-  const encoding = args.encoding === "base64" ? "base64" : "utf8";
-  fs.mkdirSync(path.dirname(args.path), { recursive: true });
-  fs.writeFileSync(safePath(args.path, args.content, encoding as BufferEncoding);
-  return { ok: true, path: args.path, size: fs.statSync(safePath(args.path).size };
+// ── C-004: file_write ───────────────────────────────────────
+export async function file_write(args: { path: string; content: string; encoding?: string }): Promise<any> {
+  const filePath = safePath(args.path);
+  fs.mkdirSync(path.dirname(filePath), { recursive: true });
+  fs.writeFileSync(filePath, args.content, (args.encoding === "base64" ? "base64" : "utf8") as BufferEncoding);
+  return { ok: true, path: filePath, size: fs.statSync(filePath).size };
 }
 
-// 鈹€鈹€ C-005: file_move 鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€
-export async function file_move(args: {
-  from: string;
-  to: string;
-}): Promise<any> {
-  fs.mkdirSync(path.dirname(safePath(args.to)), { recursive: true });
-  fs.renameSync(safePath(args.from, args.to);
-  return { ok: true, from: args.from, to: args.to };
+// ── C-005: file_move ────────────────────────────────────────
+export async function file_move(args: { from: string; to: string }): Promise<any> {
+  const fromPath = safePath(args.from);
+  const toPath = safePath(args.to);
+  fs.mkdirSync(path.dirname(toPath), { recursive: true });
+  fs.renameSync(fromPath, toPath);
+  return { ok: true, from: fromPath, to: toPath };
 }
 
-// 鈹€鈹€ C-008: exec 鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€
+// ── C-008: exec ─────────────────────────────────────────────
 function sanitizeCommand(cmd: string): string {
-  if (/[;&|`$(){}[\]<>!\\\n\r]/.test(cmd)) throw new Error(`Dangerous chars in: ${cmd.slice(0,50)}`);
+  // Allow: alphanumeric, dash, slash, dot, colon, underscore, space, equals, comma
+  if (/[^a-zA-Z0-9_./\-: =,]/.test(cmd)) throw new Error(`Dangerous chars: ${cmd.slice(0,50)}`);
   return cmd;
 }
+
 export async function exec(args: { command: string; cwd?: string; timeout?: number }): Promise<any> {
   const command = sanitizeCommand(args.command);
-  const timeout = args.timeout ?? 30000;
+  const cwd = args.cwd ? safePath(args.cwd) : process.cwd();
   try {
-    const stdout = execSync(command, {
-      cwd: args.cwd ?? process.cwd(),
-      timeout,
-      encoding: "utf8",
-      maxBuffer: 10 * 1024 * 1024, // 10MB
-      stdio: ["pipe", "pipe", "pipe"],
-    });
+    const stdout = execSync(command, { cwd, timeout: args.timeout ?? 30000, encoding: "utf8", maxBuffer: 10*1024*1024, stdio: ["pipe","pipe","pipe"] });
     return { ok: true, stdout: stdout.toString(), stderr: "" };
   } catch (err: any) {
-    return {
-      ok: false,
-      stdout: err.stdout?.toString() ?? "",
-      stderr: err.stderr?.toString() ?? "",
-      exitCode: err.status ?? -1,
-      signal: err.signal,
-    };
+    return { ok: false, stdout: err.stdout?.toString() ?? "", stderr: err.stderr?.toString() ?? "", exitCode: err.status ?? -1, signal: err.signal };
   }
 }
 
-// 鈹€鈹€ C-010: process_list 鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€
-export async function process_list(args: {
-  filter?: string;
-}): Promise<any> {
+// ── C-010: process_list ─────────────────────────────────────
+export async function process_list(args: { filter?: string }): Promise<any> {
   let stdout: string;
   try {
     if (process.platform === "win32") {
@@ -113,10 +79,7 @@ export async function process_list(args: {
     } else {
       stdout = execSync("ps aux --no-headers", { encoding: "utf8" }).toString();
     }
-  } catch {
-    return { error: "Failed to list processes" };
-  }
-
+  } catch { return { error: "Failed to list processes" }; }
   const processes = stdout.trim().split("\n").map(line => {
     if (process.platform === "win32") {
       const [name, pid, , mem] = line.replace(/"/g, "").split(",");
@@ -125,34 +88,12 @@ export async function process_list(args: {
     const parts = line.trim().split(/\s+/);
     return { user: parts[0], pid: Number(parts[1]), cpu: parts[2], mem: parts[3], name: parts[10] };
   });
-
-  const filtered = args.filter
-    ? processes.filter(p => p.name?.toLowerCase().includes(args.filter!.toLowerCase()))
-    : processes.slice(0, 50);
-
+  const filtered = args.filter ? processes.filter(p => p.name?.toLowerCase().includes(args.filter!.toLowerCase())) : processes.slice(0, 50);
   return { count: filtered.length, processes: filtered };
 }
 
-// 鈹€鈹€ C-011: sysinfo 鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€鈹€
+// ── C-011: sysinfo ──────────────────────────────────────────
 export async function sysinfo(_args: {}): Promise<any> {
-  const cpuUsage = os.loadavg();
-  const totalMem = os.totalmem();
-  const freeMem = os.freemem();
-  const uptime = os.uptime();
-
-  return {
-    hostname: os.hostname(),
-    platform: os.platform(),
-    arch: os.arch(),
-    cpus: os.cpus().length,
-    loadavg: cpuUsage,
-    memory: {
-      total: totalMem,
-      free: freeMem,
-      used: totalMem - freeMem,
-      percent: Math.round(((totalMem - freeMem) / totalMem) * 100),
-    },
-    uptime,
-    node: process.version,
-  };
+  const tm = os.totalmem(); const fm = os.freemem();
+  return { hostname: os.hostname(), platform: os.platform(), arch: os.arch(), cpus: os.cpus().length, loadavg: os.loadavg(), memory: { total: tm, free: fm, used: tm - fm, percent: Math.round(((tm-fm)/tm)*100) }, uptime: os.uptime(), node: process.version };
 }