chore: drop non-code junk (pi-mono-reference, runtime state, root duplicates)

Remove files that should never have been tracked:

- pi-mono-reference/: 688-file copy of an upstream monorepo, zero imports,
  used only as offline human reference
- build/electron-builder.runtime.json: environment-specific build artifact
  with hardcoded local paths
- state/cancel-signal-state.json: runtime state written by the app
- prompt.txt, logo.svg (root): exact duplicates of the canonical copies
  under .planning/archive/ and assets/

Add state/ to .gitignore so future runtime state stays out.

pi-mono-reference/packages/coding-agent/examples/sdk/12-full-control.ts

@@ -1,81 +0,0 @@
-/**
- * Full Control
- *
- * Replace everything - no discovery, explicit configuration.
- *
- * IMPORTANT: When providing `tools` with a custom `cwd`, use the tool factory
- * functions (createReadTool, createBashTool, etc.) to ensure tools resolve
- * paths relative to your cwd.
- */
-
-import { getModel } from "@mariozechner/pi-ai";
-import {
-	AuthStorage,
-	createAgentSession,
-	createBashTool,
-	createExtensionRuntime,
-	createReadTool,
-	ModelRegistry,
-	type ResourceLoader,
-	SessionManager,
-	SettingsManager,
-} from "@mariozechner/pi-coding-agent";
-
-// Custom auth storage location
-const authStorage = AuthStorage.create("/tmp/my-agent/auth.json");
-
-// Runtime API key override (not persisted)
-if (process.env.MY_ANTHROPIC_KEY) {
-	authStorage.setRuntimeApiKey("anthropic", process.env.MY_ANTHROPIC_KEY);
-}
-
-// Model registry with no custom models.json
-const modelRegistry = ModelRegistry.inMemory(authStorage);
-
-const model = getModel("anthropic", "claude-sonnet-4-20250514");
-if (!model) throw new Error("Model not found");
-
-// In-memory settings with overrides
-const settingsManager = SettingsManager.inMemory({
-	compaction: { enabled: false },
-	retry: { enabled: true, maxRetries: 2 },
-});
-
-// When using a custom cwd with explicit tools, use the factory functions
-const cwd = process.cwd();
-
-const resourceLoader: ResourceLoader = {
-	getExtensions: () => ({ extensions: [], errors: [], runtime: createExtensionRuntime() }),
-	getSkills: () => ({ skills: [], diagnostics: [] }),
-	getPrompts: () => ({ prompts: [], diagnostics: [] }),
-	getThemes: () => ({ themes: [], diagnostics: [] }),
-	getAgentsFiles: () => ({ agentsFiles: [] }),
-	getSystemPrompt: () => `You are a minimal assistant.
-Available: read, bash. Be concise.`,
-	getAppendSystemPrompt: () => [],
-	extendResources: () => {},
-	reload: async () => {},
-};
-
-const { session } = await createAgentSession({
-	cwd,
-	agentDir: "/tmp/my-agent",
-	model,
-	thinkingLevel: "off",
-	authStorage,
-	modelRegistry,
-	resourceLoader,
-	// Use factory functions with the same cwd to ensure path resolution works correctly
-	tools: [createReadTool(cwd), createBashTool(cwd)],
-	sessionManager: SessionManager.inMemory(),
-	settingsManager,
-});
-
-session.subscribe((event) => {
-	if (event.type === "message_update" && event.assistantMessageEvent.type === "text_delta") {
-		process.stdout.write(event.assistantMessageEvent.delta);
-	}
-});
-
-await session.prompt("List files in the current directory.");
-console.log();