refactor(dashboard,desktop,engine): remove unused imports, props, and locals

Clears the remaining no-unused-vars warnings across the dashboard app and
server, desktop main, and engine sources. Dead React state destructures are
collapsed to setter-only, unused props are underscore-prefixed to preserve
API shape, and unreferenced catch bindings are dropped. No behaviour change.

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

packages/engine/src/agent-heartbeat.ts

@@ -1073,8 +1073,8 @@ export class HeartbeatMonitor {
           },
         };
 
-        // Lazy-load createFnAgent and promptWithFallback
-        const { createFnAgent, promptWithFallback } = await import("./pi.js");
+        // Lazy-load promptWithFallback
+        const { promptWithFallback } = await import("./pi.js");
         const { createResolvedAgentSession } = await import("./agent-session-helpers.js");
         const { buildSessionSkillContextSync } = await import("./session-skill-context.js");
 

packages/engine/src/agent-session-helpers.ts

@@ -7,7 +7,7 @@
  * creation and prompting.
  */
 
-import type { AgentRuntimeOptions, AgentSessionResult } from "./agent-runtime.js";
+import type { AgentRuntimeOptions } from "./agent-runtime.js";
 import type { PluginRunner } from "./plugin-runner.js";
 import type { AgentSession } from "@mariozechner/pi-coding-agent";
 import { resolveRuntime, buildRuntimeResolutionContext, type SessionPurpose } from "./runtime-resolution.js";

packages/engine/src/agent-tools.ts

@@ -157,10 +157,6 @@ function agentDreamsDisplayPath(agentId: string): string {
   return `${AGENT_MEMORY_ROOT}/${sanitizeAgentMemoryId(agentId)}/${AGENT_DREAMS_FILENAME}`;
 }
 
-function agentDailyDisplayPath(agentId: string, date = new Date()): string {
-  return `${AGENT_MEMORY_ROOT}/${sanitizeAgentMemoryId(agentId)}/${date.toISOString().slice(0, 10)}.md`;
-}
-
 function agentMemoryDirectory(rootDir: string, agentId: string): string {
   return join(rootDir, AGENT_MEMORY_ROOT, sanitizeAgentMemoryId(agentId));
 }

packages/engine/src/executor.ts

@@ -11,7 +11,7 @@ import { findWorktreeUser } from "./merger.js";
 import { generateWorktreeName, slugify } from "./worktree-names.js";
 import { Type, type Static } from "@mariozechner/pi-ai";
 import { describeModel, promptWithFallback, compactSessionContext } from "./pi.js";
-import { createResolvedAgentSession, describeAgentModel } from "./agent-session-helpers.js";
+import { createResolvedAgentSession } from "./agent-session-helpers.js";
 import { buildSessionSkillContext } from "./session-skill-context.js";
 import { reviewStep, type ReviewVerdict } from "./reviewer.js";
 import { ModelRegistry, SessionManager, type ToolDefinition, type AgentSession } from "@mariozechner/pi-coding-agent";

packages/engine/src/merger.ts

@@ -7,7 +7,7 @@ import { existsSync } from "node:fs";
 import { join } from "node:path";
 import { getTaskMergeBlocker, type TaskStore, type MergeResult, type MergeDetails, type WorkflowStep, type WorkflowStepResult, type Settings, type AgentPromptsConfig } from "@fusion/core";
 import { resolveAgentPrompt } from "@fusion/core";
-import { describeModel, promptWithFallback, compactSessionContext } from "./pi.js";
+import { describeModel, promptWithFallback } from "./pi.js";
 import { createResolvedAgentSession } from "./agent-session-helpers.js";
 import { buildSessionSkillContext } from "./session-skill-context.js";
 import type { WorktreePool } from "./worktree-pool.js";

packages/engine/src/mission-autopilot.ts

@@ -26,7 +26,6 @@ import type {
   AutopilotStatus,
   MissionWithHierarchy,
   Slice,
-  SliceWithFeatures,
   MissionEventType,
 } from "@fusion/core";
 import { autopilotLog } from "./logger.js";

packages/engine/src/peer-exchange-service.ts

@@ -249,7 +249,6 @@ export class PeerExchangeService {
 
       // ── Settings sync: decide whether to include settings in request ──
       let shouldIncludeSettings = false;
-      let currentVersion: string | undefined;
 
       if (this.settingsSyncEnabled) {
         try {
@@ -291,7 +290,6 @@ export class PeerExchangeService {
           }
 
           if (shouldIncludeSettings) {
-            currentVersion = this.cachedSettingsPayload.checksum;
             request.settings = this.cachedSettingsPayload;
           }
         } catch (err) {

packages/engine/src/rate-limit-retry.ts

@@ -78,7 +78,6 @@ export async function withRateLimitRetry<T>(
     try {
       return await fn();
     } catch (err: unknown) {
-      const errorMessage = err instanceof Error ? err.message : String(err);
       const error = err instanceof Error ? err : new Error(String(err));
 
       // Non-rate-limit errors: re-throw immediately — no retry