chore: remove @tm/build-config package (unused after Bun migration)

The tsdown-based build config is no longer needed since the build now
uses Bun's native bundler via scripts/build.ts. Moved fix-null-versions
utility script to scripts/ and cleaned up references.

Author: Crunchyman-ralph

.manypkg.json

@@ -2,5 +2,5 @@
 	"$schema": "https://unpkg.com/@manypkg/get-packages@1.1.3/schema.json",
 	"defaultBranch": "main",
 	"ignoredRules": ["ROOT_HAS_DEPENDENCIES", "INTERNAL_MISMATCH"],
-	"ignoredPackages": ["@tm/core", "@tm/cli", "@tm/build-config"]
+	"ignoredPackages": ["@tm/core", "@tm/cli"]
 }

package.json

@@ -23,7 +23,6 @@
 		"turbo:test": "turbo test",
 		"turbo:test:unit": "turbo test:unit",
 		"turbo:test:integration": "turbo test:integration",
-		"build:build-config": "bun run build -w @tm/build-config",
 		"test": "turbo test",
 		"test:unit": "turbo test:unit",
 		"test:integration": "turbo test:integration",
@@ -45,7 +44,8 @@
 		"format-check": "biome format .",
 		"format": "biome format . --write",
 		"deps:check": "manypkg check || echo 'Note: Workspace package version warnings are expected for internal @tm/* packages'",
-		"deps:fix": "manypkg fix"
+		"deps:fix": "manypkg fix",
+		"fix-null-versions": "bun run scripts/fix-null-versions.ts"
 	},
 	"keywords": [
 		"claude",

packages/build-config/CHANGELOG.md

@@ -1,10 +1,10 @@
-#!/usr/bin/env npx tsx
+#!/usr/bin/env bun
 
 /**
  * Fixes package.json files where version is null (changeset quirk).
  * Replaces "version": null with "version": ""
  *
- * Usage: npx tsx packages/build-config/scripts/fix-null-versions.ts
+ * Usage: bun run scripts/fix-null-versions.ts
  */
 
 import { readFileSync, writeFileSync } from 'node:fs';
@@ -13,7 +13,7 @@ import { dirname, join } from 'node:path';
 import { fileURLToPath } from 'node:url';
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
-const rootDir = join(__dirname, '..', '..', '..');
+const rootDir = join(__dirname, '..');
 
 const packageFiles = globSync('**/package.json', {
 	cwd: rootDir,

packages/build-config/package.json

@@ -20,8 +20,6 @@
 			"@tm/cli/*": ["./apps/cli/src/*"],
 			"@tm/mcp": ["./apps/mcp/src/index.ts"],
 			"@tm/mcp/*": ["./apps/mcp/src/*"],
-			"@tm/build-config": ["./packages/build-config/src/index.ts"],
-			"@tm/build-config/*": ["./packages/build-config/src/*"],
 			"@tm/ai-sdk-provider-grok-cli": [
 				"./packages/ai-sdk-provider-grok-cli/src/index.ts"
 			],