tp-design-learn

name	tp-design-learn
description	Synthesize a completed design's impact into project docs updates and identify affected sibling designs. The "close the loop" step after implementation-audit.
argument-hint	{design-name} [--auto] [--force-takeover]

Design Learn

Read a completed design's artifacts and synthesize what was built into proposed updates for project docs and downstream designs.

Argument: {design-name} (required) — must match an existing directory under three-pillars-docs/tp-designs/ or three-pillars-docs/completed-tp-designs/.

Prerequisites

• design.md and implementation-audit.md (or at minimum plan.md with all tasks Done) must exist. If not, tell the user what's missing and stop.

Steps

0. Run first-run preflight per skills/_shared/first-run.md.

1. Validate {design-name} per skills/_shared/validate-name.md.

2. Locate the design directory: check three-pillars-docs/tp-designs/{design-name}/ first, then three-pillars-docs/completed-tp-designs/{design-name}/.

3. Read the full design directory: design.md, detailed-design.md, plan.md, implementation-audit.md, and any review.md files.

4. Read project docs per skills/_shared/read-project-docs.md.

5. Update Design Inventory in product_roadmap.md: If the roadmap has a Design Inventory table, find the row for {design-name} and propose updating its status to a short label + link per skills/_shared/living-doc-format.md (e.g., Done — PR #NN — [design](completed-tp-designs/…/design.md)). If the design is NOT in the table (was created before roadmap registration existed), propose adding a row. Keep the What and Status cells short — narrative belongs in the linked design or seed. Show the proposed change and get user confirmation.

6. Update Current Focus in product_roadmap.md: If the roadmap has a ## Current Focus table, propose changes:

   • Remove the completed design's row from Current Focus (it's done).
   • Update "Blocked By" on any row that listed this design as a blocker — clear the blocker if this was the only one.
   • Promote the next logical item if removing this row leaves a priority gap. Look at the Design Inventory for designs whose dependencies are now satisfied.
   • Update "Next Action" on any row whose next step changed because this design completed (e.g., a dependent design can now proceed to /tp-design-detail). Show the proposed Current Focus table and get user confirmation.

7. Propose updates for each doc that needs changes, following the pattern in skills/_shared/propose-doc-edits.md. Explain why the completed design motivates each change. For each living doc edited, follow skills/_shared/living-doc-format.md:

   • Update the *Last updated: YYYY-MM-DD* date on line 2–3.
   • Append one dated line at the top of the ## History section (newest-first): - YYYY-MM-DD — one-sentence summary. Keep it under 800 non-ws chars.

8. Learn-verification (advisory): run python3 "$TP_ROOT"/skills/_shared/verify_learn.py --range {default}...tp/{design-name} --json (where {default} is the base branch — usually master). It reports three-pillars-docs/** lines (living and completed-tp-designs/) that still name a symbol or file this design retired (deleted/renamed in the diff) — the "learn ran ≠ docs match as-built" gap. Treat any hit as a propagation miss: fold the scrub into the step-7 doc updates. Advisory only — the helper always exits 0 and fails open; never block on it. Surface any remaining hits in the step-12 report (and, in --auto, append them to decisions.md). Range note: {default}...tp/{design-name} (three-dot) diffs merge-base→tp/{design-name}, surfacing this design's deletions — not tp/{design-name}...{default}, which would surface the wrong (base) side.

   The same verify_learn.py run also surfaces stale invariant-number citations in the design's touched prose files (any file changed within the diff range that cites an invariant #N where N is not a live invariant number in framework-check.sh). These appear alongside the retired-symbol refs in the JSON output. Treat any stale-cite hit as an advisory repair prompt — update the prose to reference a live invariant or remove the stale number — but never block on it (the helper always exits 0, fail-open).

   Also run python3 "$TP_ROOT"/skills/_shared/citation_liveness.py --repo . --remote --json and fold any DeadCite or StaleRow hits into the step-7 doc updates. Advisory only — exits 0, fail-open offline; never block on it.

9. Scan for affected sibling designs: Read all design.md files under three-pillars-docs/tp-designs/ (excluding the current design). Match key concepts — new modules, changed interfaces, architecture decisions from implementation-audit.md or detailed-design.md — against each design's Scope and Entities sections. For each affected design, also check whether its declared dependencies include the current design — if so, note whether those dependency requirements are now satisfied. List affected designs with an explanation of what needs updating.

   When an affected sibling is an archived design whose documented behavior this design changed, propose the dated amendment per skills/_shared/reconcile-protocol.md. In --auto: apply the amendment and log to decisions.md with Confidence per auto-mode.md rules.

10. Vision drift check (do not auto-propose vision edits): Compare what was actually built against three-pillars-docs/vision.md. Does the implementation contradict a stated principle or non-goal? Does it serve the stated problem in a way the vision didn't anticipate? If you find a genuine tension — not a stylistic mismatch — flag it to the user with a specific citation (which implementation detail, which vision bullet) and recommend /tp-docs-update vision as an explicit follow-up. Do not propose vision edits directly from this skill. The sticky-vision principle exists to prevent post-hoc rationalization: shipped features are not evidence the vision changed.

11. Commit the doc updates per skills/_shared/commit-after-work.md. Artifact paths to stage (include only those actually modified in steps 5–9):

    • three-pillars-docs/product_roadmap.md
    • three-pillars-docs/architecture.md
    • three-pillars-docs/known_issues.md
    • three-pillars-docs/known_issues_resolved.md (when this learn resolves an issue, move its entry verbatim from known_issues.md to this archive — never mark it resolved in place) Do NOT stage three-pillars-docs/vision.md — this skill never auto-edits vision. Commit message: Learn: {design-name} design.

12. Report: Summarize what was updated, what designs are affected, any vision tensions flagged, and suggest /tp-design-complete {design-name} as the next step.

Rules

• Follow skills/_shared/propose-doc-edits.md for all doc updates.
• Works on both active (three-pillars-docs/tp-designs/) and archived (three-pillars-docs/completed-tp-designs/) designs.
• Never auto-edit three-pillars-docs/vision.md. Flag tensions, recommend /tp-docs-update vision, let the user decide.

Auto Mode

/tp-design-learn --auto follows Shape B (Generator) per skills/_shared/auto-mode.md — it derives Design Inventory updates, Current Focus updates, and architecture/known-issues/roadmap doc edits directly from the completed design's artifacts, without per-edit user confirmation.

Never auto-edits vision.md.

Behavior in --auto:

• Skip user-confirmation in steps 5, 6, and 7. Apply the proposed Design Inventory row update (step 5), the proposed Current Focus table changes (step 6), and the proposed architecture / known-issues / roadmap doc edits (step 7) directly to disk. No "show diff and wait" — just write.
• Log every diff applied as a Decision Entry in decisions.md — one entry per diff, with Confidence: High | Medium | Low and reasoning. Use the schema-v1 init/append protocol referenced inline in skills/_shared/auto-mode.md (canonical snippet — do not reimplement). The skill name prefix is [tp-design-learn].
• Step 10 (vision drift check): log tension to decisions.md and continue. If you detect a genuine tension between the implementation and three-pillars-docs/vision.md, append a Decision Entry describing the specific implementation detail and vision bullet in tension, with Confidence: Low (the user must review). Do not propose, draft, or apply any edit to vision.md. The bolded contract above (**Never auto-edits \vision.md`.**) is load-bearing: it preserves the sticky-vision principle even when no human is in the loop. Runtime enforcement of "no write to vision.md`" is deferred to D12 dogfood per the design's Out-of-band boundary.
• Step 11 (commit) still runs. Stage only the modified artifacts among product_roadmap.md, architecture.md, known_issues.md, known_issues_resolved.md — never vision.md. Commit message stays Learn: {design-name} design.
• Lock conflict is BLOCKED in --auto, not a prompt — append a BLOCKED Decision Entry and exit non-zero per skills/_shared/auto-mode.md Rule 5.

This is the acknowledged-tension shape (Shape B with logging): per design-pipeline-auto-mode/design.md Vision alignment, the "Silent mutation" tension is accepted because decisions.md captures every diff and the outcome PR is human-reviewed.