release(v1): scope consistency audit + v1.0.0 release preparation

[Krishan27]

Scope

• Align README/docs/npm/website on supported providers, languages, migration scope
• Remove stale or overpromising copy
• Draft changelog and release notes
• Version bump to v1.0.0
• Final release gate check against all P0 issues

Acceptance criteria

• All public surfaces reflect same v1.0 scope
• Changelog and release notes drafted
• Version bump PR passes release gate

Labels: v1.0, release

[Krishan27]

Duplicate of #172 — closed by PR #183.