Cut first Obsidian release and smoke-test release assets

[bobthearsonist]

Problem

Marketplace submission needs a public GitHub release containing the exact Obsidian plugin assets: manifest.json, main.js, and styles.css. PR #10 adds packaging support, but the first release and manual smoke test remain pending.

Scope

• After PR Prepare Obsidian marketplace release packaging #10 lands, run the documented package command from the repository root.
• Create the first GitHub release using a tag that exactly matches manifest.json version.
• Upload manifest.json, main.js, and styles.css from the packaged Obsidian output as top-level release assets.
• Install those release assets into a clean test vault.
• Verify plugin enablement, settings, watched-folder extraction, sidecar writing, rendering, pin or force regenerate commands, and graceful behavior with missing or invalid API key.

Acceptance criteria

• Release URL is recorded in this issue or the marketplace-readiness checklist.
• Manual smoke test results are recorded with Obsidian app version, OS, plugin version, and tested vault setup.
• No secret, private note, or local path is included in public evidence.
• Any release-asset or smoke-test failure is split into a follow-up issue before marketplace submission.