feat: synchronize universal Bun VS Code launch configuration

[artiphishle]

Goal

Make ankh devtools sync . install a universal VS Code debug configuration that is valid for every Bun-based Ankhorage repository without repository-specific paths, package names, or assumed scripts.

Required behavior

• Devtools owns .vscode/launch.json.
• The shared launch configuration uses the already recommended oven.bun-vscode debugger.
• Debug the active JavaScript/TypeScript file with:
  • type: "bun"
  • request: "launch"
  • program: "${file}"
  • cwd: "${workspaceFolder}"
  • runtime: "bun"
• Enable Bun support in the JavaScript Debug Terminal through the managed VS Code settings.
• Do not infer or hard-code repository-specific dev, start, Expo, Next.js, Studio, or other commands.
• Do not write absolute machine paths.
• Sync/status/dry-run/idempotence must cover the new managed file.
• Package the canonical launch asset in the published Devtools package.
• Update the manual usage source; do not hand-edit generated README/Paradox output.

Rationale

Issue #24 intentionally left launch.json unmanaged because application launch commands differ between libraries, CLIs, Expo, Next.js and other repositories. The Bun debugger now gives us a genuinely shared repository-independent contract: debug the active source entry file, while repository-specific package scripts remain owned by the repository and can run in the Bun-enabled Debug Terminal.

Skills to load

• .agents/skills/ankhorage-coding-rules/SKILL.md
• .agents/skills/ankhorage-project-structure/SKILL.md
• .agents/skills/hexagonal-architecture/SKILL.md

Acceptance

• .vscode/launch.json is managed by Devtools.
• No repository-specific or absolute path appears in the canonical launch configuration.
• bun.debugTerminal.enabled is centrally enabled.
• Aggregate and VS Code scoped sync/status include launch configuration.
• Repeated sync is byte-stable.
• The packaged Devtools artifact contains the launch asset.
• Changeset added.