fix(app): use HTTP-safe UUID for restored comment notes

[opencode-agent]

Summary

• Restoring a sent comment note to the composer (revert/fork) generated its commentID with crypto.randomUUID(), which is unavailable on non-local HTTP origins. It now uses the existing uuid() helper, matching the rest of the composer.
• Touching this file brings it under lint:changed, so the hand-rolled metadata parsing is replaced with Effect Schema decoding: readPromptPresentation decodes displayText, comments and attachments with the existing Persistence helpers, still skipping malformed comments/attachments individually and still returning nothing without a comments list.
• Removes readCommentMetadata and createCommentMetadata, which had no callers.

Behaviour differences, checked against the previous implementation on a table of malformed inputs: a file comment sent with type: "file" keeps that field, and a comment with an unrecognised type is now skipped instead of being read as a file comment.

Checks

• bun typecheck from packages/app
• bun test --conditions=solid --preload ./happydom.ts ./src from packages/app (730 pass)
• oxlint on comment-note.ts: 0 warnings

Requested by: @Brendonovich (Brendan via Slack)