refactor(agentos): split ideation-sandbox §5.1 divergence from convergence (#12441) (#12475)

Split the Double Diamond §5.1 matrix into a 3-col pure-divergence matrix (open for peer-added rows) + a gated convergence pass opened after a time-boxed divergence window. Add correlation-ceiling, comment-anchored option-cards, and valid-options reject-at-entry. Move the §3 change-log to bottom-of-body. Rule bodies in the audit (World Atlas); §5.1 compressed + net-reduced under the per-file budget.

Resolves #12441
Refs #12436

Co-authored-by: tobiu <tobiasuhlig78@gmail.com>

Author: neo-opus-ada

.agents/skills/ideation-sandbox/audits/double-diamond-divergence-guard.md

@@ -22,17 +22,30 @@ Empirical anchors:
 
 Mandatory high-blast-radius Discussion graduations cover Epics, new skill/rule/workflow changes, and substrate-level architecture changes. Standalone tickets keep the matrix optional/recommended unless a peer or operator marks the proposal high-blast-radius.
 
-Matrix floor:
+Divergence matrix floor (pure-divergence — NO adopt/reject, NO author-lean column):
 
-| Option | When this would be right | Evidence / falsifier | Rationale | Residual risk |
-|---|---|---|---|---|
+| Option | When this would be right | Evidence / falsifier |
+|---|---|---|
 
-Rejected options require at least one falsifying source: prior commit, precedent code, KB result, Memory Core result, prior issue / PR / discussion, or explicit `"no source found after query X"`. Include at least two alternative shapes beside the recommended one.
+Each option (incl. later-rejected ones) requires at least one falsifying source: prior commit, precedent code, KB result, Memory Core result, prior issue / PR / discussion, or explicit `"no source found after query X"`. Include at least two alternative shapes beside the recommended one. The matrix is **open for peer-added rows** — the divergent half of design is *peers adding options*, not pressuring the author's.
+
+**Valid options only (reject-at-entry).** A matrix row must be a plausible/valid candidate. Reject categorically-invalid / strawman / impossible options **at entry**, not at the §5.2 Step-Back — an invalid option pollutes the divergence frame from the start. This is distinct from the divergence-theater guard below (which targets low-effort throwaway filler): an articulated-but-invalid option (e.g. "one subtractive PR" for a 20-sub epic, or "lint-first" conflating the lint with the inventory method) is wrong, not lazy, and the window-gate would not catch it.
+
+**Divergence window, not per-peer count.** Gate the convergence pass on a time-boxed divergence **window**, never a per-peer option count — a count breeds divergence-*theater* (low-effort filler to clear the gate). Quality is enforced at the §5.2 Step-Back. Peers may submit options asynchronously as **comment-anchored option-cards**: one comment per option, shaped `Option <X>: <one-line> | when-right: … | falsifier: …`, which the author folds into the body matrix.
+
+**Correlation-ceiling.** At least one divergence option MUST be sourced from **outside the awake-peer-set** — prior-art via `ask_knowledge_base`, or the §2.2 precedent sweep elevated to a required option-source. The liveness cap means 1–2 same-family awake peers share correlated blind spots; an outside-sourced option counters that.
+
+Gated convergence pass (opens only after the window closes):
+
+| Option | Adoption / rejection rationale | Residual risk |
+|---|---|---|
+
+The convergence columns (adopt/reject + author-lean + residual-risk) are filled **after** the divergence window closes. Filling them during the window re-introduces the pre-converged frame that makes peers pressure the author's options instead of widening the space.
 
 Process gate:
 
-- Matrix appears in the Discussion body before any `[RESOLVED_TO_AC]` tags.
-- At least one non-author peer review cycle occurs after matrix insertion and before `GRADUATED`.
+- The divergence matrix appears in the Discussion body before any `[RESOLVED_TO_AC]` tags.
+- At least one non-author peer cycle occurs during the divergence window (after matrix insertion, before the window closes and `GRADUATED`).
 - Retro-fitted matrices after OQ resolution are paperwork; they capture convergence, not divergence.
 
 ## Ticket-Create Exception

.agents/skills/ideation-sandbox/references/ideation-sandbox-workflow.md

@@ -30,7 +30,7 @@ Before Discussion prose, read [`reference-hygiene.md`](../../../../learn/agentos
 ## 3. Author's Note Convention (The `#10119` Annotation Pattern)
 Discussions are meant to evolve. Instead of creating noisy parallel comment threads to reflect updates to the core idea, the authoritative substrate is the Discussion body itself.
 - Use **"the `#10119` annotation pattern"**: Treat the Discussion body like a PR diff. When the idea evolves, edit the body directly with `manage_discussion({action: 'update_body', discussion_number, body})` (like a force-push).
-- Add top-of-body annotation markers (e.g. `> **Update 2026-04-24:** Refined the VDOM syncing section based on feedback below.`) to signal what changed.
+- Add annotation markers at the **bottom of the body** (or use re-poll-comment deltas) so the **proposal leads** — e.g. `> **Update 2026-04-24:** Refined a section per feedback.`
 - You may add a brief comment to notify thread participants, but the body remains the single source of truth.
 
 ## 4. Iterative Review Workflow
@@ -54,21 +54,18 @@ A Discussion cannot graduate until it is clearly scoped. There is no universal c
 
 **Trigger — mandatory cases:** if the Discussion intends to graduate to (a) an Epic, (b) a new skill / rule / workflow change, or (c) a substrate-level architecture change, the divergence matrix below is **MANDATORY** before graduation. For standalone tickets (`[GRADUATED_TO_TICKET]`) the matrix is **optional but recommended** unless a peer or the operator marks the proposal high-blast-radius.
 
-**Matrix floor (5 columns, mandatory):**
+**Divergence matrix floor (3 columns — pure-divergence, mandatory):**
 
-| Option | When this would be right | Evidence / falsifier (≥1 source per rejected option) | Adoption or rejection rationale | Residual risk |
-|---|---|---|---|---|
+| Option | When this would be right | Evidence / falsifier (≥1 source per option) |
+|---|---|---|
 
-- Each rejected option MUST cite at least one falsifying source, and at least 2 alternative shapes must be enumerated beside the recommendation.
+- **No adopt/reject + no author-lean column**; the matrix is **open for peer-added rows** (peers ADD options, not pressure the author's), ≥2 alternatives each with ≥1 falsifying source. Adopt/reject + residual-risk move to a separate **gated convergence pass** after the divergence window closes.
 
-**Process gate — matrix authored BEFORE convergence:**
-
-- The matrix MUST appear in the Discussion body **before any `[RESOLVED_TO_AC]` tags are applied**. Matrices retro-fitted after OQ resolution are paperwork, not divergence — they capture the convergent answer rather than preserving the alternatives that were genuinely considered.
-- After matrix is in the body, **at least one non-author peer review cycle MUST occur before `GRADUATED`**. The peer cycle pressures the matrix's depth and falsifying sources; author-only graduation skips the divergent-pressure half of design.
+**Process gate:** divergence matrix in the body before any `[RESOLVED_TO_AC]` tag; ≥1 non-author peer cycle during the **divergence window** (peers ADD options); the **gated convergence pass** opens only after the window closes.
 
 **Graduation block:** if the matrix is missing OR lacks falsifying sources, downstream Epic / ticket creation is blocked per `epic-review-workflow.md` Stage 2 Discussion-origin backstop and per `ticket-create-workflow.md` §1c ungraduated-Discussion cross-check (substantive-rationale exception path documented there for legitimate edge cases). **Per §6 Consensus Mandate (high-blast classes only)**, graduation is ALSO blocked when the Signal Ledger lacks the §6.2 quorum (floor-2 active families with signal + ≥ 1 non-author family APPROVED; Tier-2 also requires `## Unresolved Liveness` + `revalidationTrigger` AC) or has unresolved DEFERRED/VETO; see §6 below for full 2-axis substrate.
 
-For source anchors, exception semantics, and substrate-decay review, read [`../audits/double-diamond-divergence-guard.md`](../audits/double-diamond-divergence-guard.md).
+The full divergence rules (valid-options-only, correlation-ceiling, option-cards, gated convergence columns), source anchors, and exception semantics are in [`../audits/double-diamond-divergence-guard.md`](../audits/double-diamond-divergence-guard.md).
 
 ### 5.1.1. Reflective Pause Trigger (Friction-Driven Proposals)