docs: prepare v0.6 release authority

[davidahmann]

Problem

A public release needs a reviewed authority record and an immutable release note before an annotated tag can enter qualification. The v0.5 candidate failed before publication, so its tag and inputs cannot be reused.

Changes

• Add the immutable v0.6 candidate release note.
• Add the attended release authority, approved impact, and bounded release task for v0.6.
• Close the merged guided-operations source task and make the v0.6 release task the sole active task.
• Keep provider results for the later post-release closure PR rather than rewriting the tagged release note.

Validation

• npm run check (364 tests passed)
• node dist/cli.js --json --cwd . audit

Risk

This PR creates no tag, npm publication, GitHub Release, or npm environment rule. Those separately authorized effects follow only after this reviewed record merges.