feat(09-01): define granular event types, IPC channels, entity getters, and Zustand patch methods

- Add 5 granular event interfaces (TaskUpdated, RunUpdated, ApprovalUpdated, AgentUpdated, BudgetChanged) to DesktopEvent union
- Add 4 entity getter IPC channels (getTask, getAgent, getRun, getApproval) with Zod validation and company ownership checks
- Add getRun method to AppDatabase following existing getTask pattern
- Add 4 preload bridge methods for entity getters
- Add 8 patch/remove methods and refreshBadges to CompanySlice
- Add selective-ipc.test.ts with exhaustive union type tests
- Extend store.test.ts with 14 patch method tests

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/main/ipc-core-read-handlers.ts

@@ -4,6 +4,7 @@ import { z } from "zod";
 import {
   IPC_CHANNELS,
   connectorInputSchema,
+  entityGetterSchema,
   metricsQuerySchema,
   settingsSchema,
 } from "@shared/contracts";
@@ -142,4 +143,58 @@ export function registerCoreReadHandlers({
     if (err) return err;
     return ok(db.getStandupReport(companyId));
   });
+
+  // --- Entity getters for granular IPC updates ---
+
+  registerHandle(IPC_CHANNELS.getTask, (_event, payload) => {
+    const parsed = entityGetterSchema.parse(payload);
+    const companyError = ensureCompanyExists(parsed.companyId);
+    if (companyError) return companyError;
+    try {
+      const task = db.getTask(parsed.id);
+      if (task.companyId !== parsed.companyId) return fail("TASK_NOT_FOUND", "Task not found in current company.");
+      return ok(task);
+    } catch {
+      return fail("TASK_NOT_FOUND", "Task not found.");
+    }
+  });
+
+  registerHandle(IPC_CHANNELS.getAgent, (_event, payload) => {
+    const parsed = entityGetterSchema.parse(payload);
+    const companyError = ensureCompanyExists(parsed.companyId);
+    if (companyError) return companyError;
+    try {
+      const agent = db.getAgent(parsed.id);
+      if (agent.companyId !== parsed.companyId) return fail("AGENT_NOT_FOUND", "Agent not found in current company.");
+      return ok(agent);
+    } catch {
+      return fail("AGENT_NOT_FOUND", "Agent not found.");
+    }
+  });
+
+  registerHandle(IPC_CHANNELS.getRun, (_event, payload) => {
+    const parsed = entityGetterSchema.parse(payload);
+    const companyError = ensureCompanyExists(parsed.companyId);
+    if (companyError) return companyError;
+    try {
+      const run = db.getRun(parsed.id);
+      if (run.companyId !== parsed.companyId) return fail("RUN_NOT_FOUND", "Run not found in current company.");
+      return ok(run);
+    } catch {
+      return fail("RUN_NOT_FOUND", "Run not found.");
+    }
+  });
+
+  registerHandle(IPC_CHANNELS.getApproval, (_event, payload) => {
+    const parsed = entityGetterSchema.parse(payload);
+    const companyError = ensureCompanyExists(parsed.companyId);
+    if (companyError) return companyError;
+    try {
+      const approval = db.getApprovalRecord(parsed.id);
+      if (approval.companyId !== parsed.companyId) return fail("APPROVAL_NOT_FOUND", "Approval not found in current company.");
+      return ok(approval);
+    } catch {
+      return fail("APPROVAL_NOT_FOUND", "Approval not found.");
+    }
+  });
 }