refactor: apply minimal tfcode branding

- Rename packages/opencode → packages/tfcode (directory only)
- Rename bin/opencode → bin/tfcode (CLI binary)
- Rename .opencode → .tfcode (config directory)
- Update package.json name and bin field
- Update config directory path references (.tfcode)
- Keep internal code references as 'opencode' for easy upstream sync
- Keep @opencode-ai/* workspace package names

This minimal branding approach allows clean merges from upstream
opencode repository while providing tfcode branding for users.

packages/tfcode/test/lsp/launch.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+import { spawn } from "../../src/lsp/launch"
+import { tmpdir } from "../fixture/fixture"
+
+describe("lsp.launch", () => {
+  test("spawns cmd scripts with spaces on Windows", async () => {
+    if (process.platform !== "win32") return
+
+    await using tmp = await tmpdir()
+    const dir = path.join(tmp.path, "with space")
+    const file = path.join(dir, "echo cmd.cmd")
+
+    await fs.mkdir(dir, { recursive: true })
+    await Bun.write(file, "@echo off\r\nif %~1==--stdio exit /b 0\r\nexit /b 7\r\n")
+
+    const proc = spawn(file, ["--stdio"])
+
+    expect(await proc.exited).toBe(0)
+  })
+})