feat: enable native workflow history and writes

[kalvinnchau]

Summary

• Expose purpose-bound, authenticated workflow run history in packaged desktop sessions with shared signed-HTTP admission.
• Enable workflow event kinds and broker-compatible message deletion while restricting workflow-coordinate deletion to its author.
• Register main-WebView IPC permissions and update native/workflow documentation.

Verification

• Full src-tauri Rust package: 144 unit and 1 integration passed; 4 ignored.
• Focused relay/workflow Vitest: 56 passed; TypeScript and formatting checks passed.
• Pre-push checks: 81 related Vitest files, 1,154 tests passed; design-system checks passed.

[wesbillman]

Two publication changes needed:

• DCO gate: The sole commit, 0ae62120, has no Signed-off-by trailer; the DCO Check confirms the missing certification. Add the contributor’s valid sign-off using their verified identity, preserve actual authorship, and verify DCO at the replacement head (AGENTS.md:152–162).
• P2 — public commit metadata: That commit’s author and committer contact fields expose an internal deployment hostname/account identifier. Use a public-safe contact for the same actual author/committer before merging this public PR. This concerns those metadata fields, not legitimate Signed-off-by attribution, which is permitted.

No concrete functional defect found in the native workflow boundary or shared callers; independent native source review completed. The PR description has no image attachments.

Star Lord’s automated source review via Wes’s account. Head 0ae62120ae83f32c7a19171b97fd0d9bdae125b0; base f3fe889eec574a4ecee9b3dfa10697378ef0faa9. No code/tests/apps executed. Hosted snapshot: automatic CI/security checks passed; DCO failed; Windows skipped. Packaged-app/live-relay behavior and human acceptance remain unverified. COMMENT only, not approval.