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/scripts/sync-versions.js

@@ -1,96 +0,0 @@
-#!/usr/bin/env node
-
-/**
- * Syncs ALL @mariozechner/* package dependency versions to match their current versions.
- * This ensures lockstep versioning across the monorepo.
- */
-
-import { readFileSync, writeFileSync, readdirSync } from 'fs';
-import { join } from 'path';
-
-const packagesDir = join(process.cwd(), 'packages');
-const packageDirs = readdirSync(packagesDir, { withFileTypes: true })
-	.filter(dirent => dirent.isDirectory())
-	.map(dirent => dirent.name);
-
-// Read all package.json files and build version map
-const packages = {};
-const versionMap = {};
-
-for (const dir of packageDirs) {
-	const pkgPath = join(packagesDir, dir, 'package.json');
-	try {
-		const pkg = JSON.parse(readFileSync(pkgPath, 'utf8'));
-		packages[dir] = { path: pkgPath, data: pkg };
-		versionMap[pkg.name] = pkg.version;
-	} catch (e) {
-		console.error(`Failed to read ${pkgPath}:`, e.message);
-	}
-}
-
-console.log('Current versions:');
-for (const [name, version] of Object.entries(versionMap).sort()) {
-	console.log(`  ${name}: ${version}`);
-}
-
-// Verify all versions are the same (lockstep)
-const versions = new Set(Object.values(versionMap));
-if (versions.size > 1) {
-	console.error('\n❌ ERROR: Not all packages have the same version!');
-	console.error('Expected lockstep versioning. Run one of:');
-	console.error('  npm run version:patch');
-	console.error('  npm run version:minor');
-	console.error('  npm run version:major');
-	process.exit(1);
-}
-
-console.log('\n✅ All packages at same version (lockstep)');
-
-// Update all inter-package dependencies
-let totalUpdates = 0;
-for (const [dir, pkg] of Object.entries(packages)) {
-	let updated = false;
-	
-	// Check dependencies
-	if (pkg.data.dependencies) {
-		for (const [depName, currentVersion] of Object.entries(pkg.data.dependencies)) {
-			if (versionMap[depName]) {
-				const newVersion = `^${versionMap[depName]}`;
-				if (currentVersion !== newVersion) {
-					console.log(`\n${pkg.data.name}:`);
-					console.log(`  ${depName}: ${currentVersion} → ${newVersion}`);
-					pkg.data.dependencies[depName] = newVersion;
-					updated = true;
-					totalUpdates++;
-				}
-			}
-		}
-	}
-	
-	// Check devDependencies
-	if (pkg.data.devDependencies) {
-		for (const [depName, currentVersion] of Object.entries(pkg.data.devDependencies)) {
-			if (versionMap[depName]) {
-				const newVersion = `^${versionMap[depName]}`;
-				if (currentVersion !== newVersion) {
-					console.log(`\n${pkg.data.name}:`);
-					console.log(`  ${depName}: ${currentVersion} → ${newVersion} (devDependencies)`);
-					pkg.data.devDependencies[depName] = newVersion;
-					updated = true;
-					totalUpdates++;
-				}
-			}
-		}
-	}
-	
-	// Write if updated
-	if (updated) {
-		writeFileSync(pkg.path, JSON.stringify(pkg.data, null, '\t') + '\n');
-	}
-}
-
-if (totalUpdates === 0) {
-	console.log('\nAll inter-package dependencies already in sync.');
-} else {
-	console.log(`\n✅ Updated ${totalUpdates} dependency version(s)`);
-}