Add Zed support to setup

[FNDEVVE]

Summary

Closes #145.

Adds Zed as a first-class editor target in effect-tsgo setup, following the existing VS Code setup flow while targeting TypeScript 7's native typescript-ls server.

Behavior

• adds interactive and non-interactive Zed selection, including --zed / --no-zed
• configures typescript-ls with the current platform package binary and --lsp --stdio
• makes typescript-ls the TypeScript and TSX server while disabling typescript-language-server and vtsls
• preserves existing .zed/settings.json JSONC structure, comments, formatting, unrelated LSP configuration, formatter settings, code actions, and explicit server ordering
• keeps JavaScript and JSX settings untouched
• aborts with actionable guidance when required Zed containers have incompatible shapes
• rejects malformed existing editor settings instead of treating them as absent or overwriting them
• emits restart guidance only when a Zed settings change is produced

Examples

New Zed configuration:

{
  "lsp": {
    "typescript-ls": {
      "binary": {
        "path": "./node_modules/@typescript/typescript-<platform>-<arch>/lib/tsc",
        "arguments": ["--lsp", "--stdio"]
      }
    }
  },
  "languages": {
    "TypeScript": {
      "language_servers": ["typescript-ls", "!typescript-language-server", "!vtsls", "..."]
    },
    "TSX": {
      "language_servers": ["typescript-ls", "!typescript-language-server", "!vtsls", "..."]
    }
  }
}

Existing settings are migrated surgically. For example, Oxlint/Oxfmt configuration, legacy initialization options, comments, trailing commas, and unrelated language-server entries remain intact.

Verification

• focused setup/config suite: 105 tests passed
• @effect/tsgo TypeScript check passed
• root lint passed
• root check passed
• root test suite passed: 138 tests
• migration test verifies valid JSONC output, exact native server configuration, preservation, and byte-identical second apply
• malformed-file test verifies diagnostics, no overwrite, and no restart guidance
• git diff --check passed