v2.0.0-beta: write tools, pending-changes queue, inference loop, API routes

Phase 2 of v2.0. BooCoder is now a functional write-capable chatbot.

Write-path guard: resolveWritePath() uses resolve() (no realpath — files may
not exist for creates) + prefix-check + secret-file deny list (.env, *.pem,
id_rsa*, etc.). 23 unit tests cover traversal attacks.

Pending-changes service: queueEdit/Create/Delete → applyOne/All →
rejectOne/All → rewindOne. Edit diffs stored as JSON {old, new}. All writes
queue before touching disk; apply re-validates the path guard.

5 write tools: edit_file, create_file, delete_file, apply_pending, rewind.
Registered alongside 25 read-only tools from BooChat (30 total, alpha-sorted).
Write tools use a module-level inference context for sql+sessionId injection.

Inference loop via workspace dependency: apps/coder imports
createInferenceRunner, createBroker, ALL_TOOLS from @boocode/server (dist/).
apps/server gains declaration: true + exports map with typed subpath entries.
No code duplication — one inference engine shared by both apps.

API routes: POST /api/sessions/:id/messages (user msg → inference), POST stop,
GET/POST pending-changes CRUD (5 endpoints), WebSocket session streaming.

Dockerfile updated to build apps/server first (coder depends on its .d.ts).
Health endpoint reports tool count: {"ok":true,"db":true,"tools":30}.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/coder/src/services/tools/create_file.ts

@@ -0,0 +1,51 @@
+import { z } from 'zod';
+import type { ToolDef, ToolContext } from './types.js';
+import { queueCreate } from '../pending_changes.js';
+
+const CreateFileInput = z.object({
+  file_path: z.string().min(1),
+  content: z.string(),
+});
+type CreateFileInputT = z.infer<typeof CreateFileInput>;
+
+export const createFileTool: ToolDef<CreateFileInputT> = {
+  name: 'create_file',
+  description:
+    'Queue creation of a new file with the given content. ' +
+    'The change is staged in pending_changes and must be applied explicitly.',
+  inputSchema: CreateFileInput,
+  jsonSchema: {
+    type: 'function',
+    function: {
+      name: 'create_file',
+      description:
+        'Queue creation of a new file with the given content. ' +
+        'The change is staged in pending_changes and must be applied explicitly.',
+      parameters: {
+        type: 'object',
+        properties: {
+          file_path: { type: 'string', description: 'Path for the new file (relative to project root or absolute)' },
+          content: { type: 'string', description: 'Full content of the file to create' },
+        },
+        required: ['file_path', 'content'],
+      },
+    },
+  },
+  async execute(input: CreateFileInputT, projectRoot: string, context: ToolContext): Promise<unknown> {
+    const change = await queueCreate(
+      context.sql,
+      context.sessionId,
+      context.taskId,
+      input.file_path,
+      input.content,
+      projectRoot,
+    );
+    return {
+      status: 'queued',
+      change_id: change.id,
+      file_path: change.file_path,
+      operation: 'create',
+      message: `File creation queued: ${change.file_path}. Use apply_pending to write changes to disk.`,
+    };
+  },
+};