emrg: promote task — host-authorized account registration + blog publishing

[argszero]

Two host-authorized extensions to the community promotion task (rants 2026-08-15T09:04:28 + 09:06:12), batched into one PR (both edit emrg/server/promote_prompt.md, stacked on #798 which is already merged).

Account registration (host-authorized) — replaces the blanket Forbidden line 🛑 No auto-creating/managing social accounts:

• New Account Registration section: MAY auto-register when a channel has no account, PROVIDED (1) registration can be completed automatically (browser harness / API; human-only steps like SMS/captcha → mark blocked (registration needs human)), (2) never register a duplicate (reuse existing accounts), (3) respect the channel's registration rules.
• State file: new channel accounts field (channel + username + registered time + source [auto-registered | host-provided]); checked before any registration.
• §0.3 channel availability flow now includes the register-or-blocked decision path.
• Red line 7: registered accounts are long-term assets (maintain, single-purpose per channel).

Blog publishing (deep content) — blogs as a formal deep-content channel:

• Channel table: new Blogs row (blogger.com / Dev.to / Medium), low cadence ≤1 post/week.
• New Blog Publishing section: topic sources (design philosophy / architecture decisions / latest progress / lessons), content requirements (depth > length, honest, consistent with emrg: promote task de-hardening — homework-first participation, disclosure default OFF #798), §0.4 fact-checking, cadence, distribution (own blog + optional cross-post), state-file records.
• State file: new blog posts + blog drafts fields; §0.4 now records new releases/milestones into blog drafts as topic candidates.

Both are prompt-only edits. Tests: new test_promote_template_registration_blog_sections (16 assertions incl. negative discrimination that the blanket Forbidden ban is gone); pytest 825 collected / 824 passed, 1 skipped; Agent.md count synced; import + CLI green.

[argszero]

✅ LGTM — cycle. Reviewed full diff: promote_prompt.md host-authorized Account Registration (§2.x, 3 preconditions + state-file channel accounts + §0.3 register-or-blocked flow + red-line-7 asset maintenance) and Blog Publishing (§2.y, topic sources / content requirements / §0.4 fact-checking / ≤1 post/week cadence / distribution / blog posts+drafts state fields); blanket Forbidden ban removed with negative-discrimination test coverage. Local verification: full suite 824 passed / 1 skipped, import + CLI green; CI test + test-windows both pass.

[argszero]

✅ LGTM — cycle. Fresh review on current head: Account Registration (host-authorized) with the 3 preconditions (can-complete / never-register-duplicate / respect channel rules), Forbidden blanket ban removed, §0.3 register-or-blocked flow, red line 7 account-asset maintenance, channel accounts state field; Blog Publishing section (blogger/Dev.to/Medium, topics/quality/cadence ≤1 post/week/distribution), Blogs channel-table row, blog posts + blog drafts fields, §0.4→blog-drafts linkage. New 16-assertion regression test incl. negative discrimination (blanket ban absent); full suite 825 collected / 824 passed, 1 skipped locally; Agent.md count synced; import + CLI green. CI test + test-windows PASS; MERGEABLE/CLEAN.

[pm25coder]

I tested this PR end-to-end on Windows and it checks out clean.

[argszero]

✅ LGTM — cycle 3/3. Fresh verification on current head (4ac56b2): full diff re-checked (promote_prompt.md account registration + blog publishing, test_promote_template_registration_blog_sections 16 assertions, Agent.md 824→825 synced); local promote tests 4 passed; full suite 824 passed / 1 skipped; import + CLI green; CI test + test-windows PASS; MERGEABLE/CLEAN. Three consecutive ✅ from different cycles — merging.