feat: Extend AgentInfo with exitCode + add getAgentInputFiles/getAgentPrompt tRPC procedures

Adds exitCode to AgentInfo type and propagates it through all toAgentInfo()
implementations. Enhances getAgent to also return taskName and initiativeName
from their respective repositories. Adds two new filesystem-reading tRPC
procedures for the Agent Details tab: getAgentInputFiles (reads .cw/input/
files with binary detection, 500 KB cap, sorted) and getAgentPrompt (reads
.cw/agent-logs/<name>/PROMPT.md with 1 MB cap and structured ENOENT handling).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/server/trpc/routers/agent.ts

@@ -5,11 +5,13 @@
 import { TRPCError } from '@trpc/server';
 import { z } from 'zod';
 import { tracked, type TrackedEnvelope } from '@trpc/server';
+import path from 'path';
+import fs from 'fs/promises';
 import type { ProcedureBuilder } from '../trpc.js';
 import type { TRPCContext } from '../context.js';
 import type { AgentInfo, AgentResult, PendingQuestions } from '../../agent/types.js';
 import type { AgentOutputEvent } from '../../events/types.js';
-import { requireAgentManager, requireLogChunkRepository } from './_helpers.js';
+import { requireAgentManager, requireLogChunkRepository, requireTaskRepository, requireInitiativeRepository } from './_helpers.js';
 
 export const spawnAgentInputSchema = z.object({
   name: z.string().min(1).optional(),
@@ -120,7 +122,23 @@ export function agentProcedures(publicProcedure: ProcedureBuilder) {
     getAgent: publicProcedure
       .input(agentIdentifierSchema)
       .query(async ({ ctx, input }) => {
-        return resolveAgent(ctx, input);
+        const agent = await resolveAgent(ctx, input);
+
+        let taskName: string | null = null;
+        let initiativeName: string | null = null;
+
+        if (agent.taskId) {
+          const taskRepo = requireTaskRepository(ctx);
+          const task = await taskRepo.findById(agent.taskId);
+          taskName = task?.name ?? null;
+        }
+        if (agent.initiativeId) {
+          const initiativeRepo = requireInitiativeRepository(ctx);
+          const initiative = await initiativeRepo.findById(agent.initiativeId);
+          initiativeName = initiative?.name ?? null;
+        }
+
+        return { ...agent, taskName, initiativeName };
       }),
 
     getAgentByName: publicProcedure
@@ -246,5 +264,106 @@ export function agentProcedures(publicProcedure: ProcedureBuilder) {
           cleanup();
         }
       }),
+
+    getAgentInputFiles: publicProcedure
+      .input(z.object({ id: z.string().min(1) }))
+      .output(z.object({
+        files: z.array(z.object({
+          name: z.string(),
+          content: z.string(),
+          sizeBytes: z.number(),
+        })),
+        reason: z.enum(['worktree_missing', 'input_dir_missing']).optional(),
+      }))
+      .query(async ({ ctx, input }) => {
+        const agent = await resolveAgent(ctx, { id: input.id });
+
+        const worktreeRoot = path.join(ctx.workspaceRoot!, 'agent-workdirs', agent.worktreeId);
+        const inputDir = path.join(worktreeRoot, '.cw', 'input');
+
+        // Check worktree root exists
+        try {
+          await fs.stat(worktreeRoot);
+        } catch {
+          return { files: [], reason: 'worktree_missing' as const };
+        }
+
+        // Check input dir exists
+        try {
+          await fs.stat(inputDir);
+        } catch {
+          return { files: [], reason: 'input_dir_missing' as const };
+        }
+
+        // Walk inputDir recursively
+        const entries = await fs.readdir(inputDir, { recursive: true, withFileTypes: true });
+        const MAX_SIZE = 500 * 1024;
+        const results: Array<{ name: string; content: string; sizeBytes: number }> = [];
+
+        for (const entry of entries) {
+          if (!entry.isFile()) continue;
+          // entry.parentPath is available in Node 20+
+          const dir = (entry as any).parentPath ?? (entry as any).path;
+          const fullPath = path.join(dir, entry.name);
+          const relativeName = path.relative(inputDir, fullPath);
+
+          try {
+            // Binary detection: read first 512 bytes
+            const fd = await fs.open(fullPath, 'r');
+            const headerBuf = Buffer.alloc(512);
+            const { bytesRead } = await fd.read(headerBuf, 0, 512, 0);
+            await fd.close();
+            if (headerBuf.slice(0, bytesRead).includes(0)) continue; // skip binary
+
+            const raw = await fs.readFile(fullPath);
+            const sizeBytes = raw.length;
+            let content: string;
+            if (sizeBytes > MAX_SIZE) {
+              content = raw.slice(0, MAX_SIZE).toString('utf-8') + '\n\n[truncated — file exceeds 500 KB]';
+            } else {
+              content = raw.toString('utf-8');
+            }
+            results.push({ name: relativeName, content, sizeBytes });
+          } catch {
+            continue; // skip unreadable files
+          }
+        }
+
+        results.sort((a, b) => a.name.localeCompare(b.name));
+        return { files: results };
+      }),
+
+    getAgentPrompt: publicProcedure
+      .input(z.object({ id: z.string().min(1) }))
+      .output(z.object({
+        content: z.string().nullable(),
+        reason: z.enum(['prompt_not_written']).optional(),
+      }))
+      .query(async ({ ctx, input }) => {
+        const agent = await resolveAgent(ctx, { id: input.id });
+
+        const promptPath = path.join(ctx.workspaceRoot!, '.cw', 'agent-logs', agent.name, 'PROMPT.md');
+
+        let raw: string;
+        try {
+          raw = await fs.readFile(promptPath, 'utf-8');
+        } catch (err: any) {
+          if (err?.code === 'ENOENT') {
+            return { content: null, reason: 'prompt_not_written' as const };
+          }
+          throw new TRPCError({
+            code: 'INTERNAL_SERVER_ERROR',
+            message: `Failed to read prompt file: ${String(err)}`,
+          });
+        }
+
+        const MAX_BYTES = 1024 * 1024; // 1 MB
+        if (Buffer.byteLength(raw, 'utf-8') > MAX_BYTES) {
+          const buf = Buffer.from(raw, 'utf-8');
+          raw = buf.slice(0, MAX_BYTES).toString('utf-8') + '\n\n[truncated — prompt exceeds 1 MB]';
+        }
+
+        return { content: raw };
+      }),
   };
 }