15000x · 09 — Lessons + carry-forward

Lessons (new this macro)

L1 — Sidecar tables beat column-adds for productizing live infra

iu_piece_collection is read by 9+ live functions and 4 live views. Adding is_template / instantiated_from columns would touch every caller; ALTER TABLE is also harder to roll back when rows reference the new state. Two sidecar tables keyed on collection_id give the same expressive power at zero blast radius. Views (v_iu_product_template, v_iu_product_template_instance) reconstitute the "all in one row" feel without owning the data.

Rule: when productizing a marker / lineage on top of an actively-joined table, prefer sidecar PK=FK table + view, not column-add.

L2 — Pinning tests are part of the migration, not test-suite hygiene

First full-suite run after 031 failed 12 tests pinning ('table',25) / ('view',24) / ('function',59) literals (and one len(governed)=20). These are the trip wire that catches a forgotten conformance-scan bump — they SHOULD fail when surface counts move. Bump them in the same commit as the migration that moved the counts, per [[feedback-pinning-tests-bump-per-macro]].

Operational tip: before full-suite run, grep -rnE "\('(table|view|function)',N\)" tests/ (with N = current pinning) returns the complete bump-list deterministically.

L3 — Birth-gate warnings are not failures (but noise is real)

fn_iu_compose emits one WARNING per minted piece: Birth gate L1 PILOT-ONLY: P-pub2 missing — production sẽ BLOCK. Didn't block the 10 piece births. Per 12000x carry-forward, needs triage — either silence when PILOT is intentional, or opt out of the hook for iu_core/template/* canonical addresses. Carry-forward to 16000x.

L4 — Composer-gate toggle inside a TX is the cleanest productization pattern

The 12000x bounded BEGIN/ROLLBACK pattern also works for durable COMMIT-ed work, simply by re-closing the gate before COMMIT:

BEGIN;
UPDATE dot_config SET value='true'  WHERE key='iu_core.composer_enabled';
-- durable composer work --
UPDATE dot_config SET value='false' WHERE key='iu_core.composer_enabled';
COMMIT;  -- gate matches pre-state; compositions are durable

Already in memory as [[feedback-in-tx-gate-toggle-reversibility]] — extended here from rehearsal to durable productization.

Memory entries proposed (3)

1. [[feedback-sidecar-over-column-add-for-live-infra]] (NEW) — see L1
2. [[feedback-pinning-tests-bump-per-macro]] (REFRESH) — extend with grep command + note 15000x bumped 12 tests
3. [[project-dot_iu_cutter_v0_6_iu_core_15000x_productization_operator_ops_closeout]] (NEW) — full project entry

Carry-forward to 16000x+

#	Item	Target
1	Birth-gate PILOT noise — fix P-pub2 missing warning	16000x
2	Template versioning lineage column (parent_template_id on registry)	16000x
3	Bulk export of template-bundle (collection + pieces + manifest)	16000x
4	Live (non-dry-run) piece event delivery	17000x
5	VPS Linux timer / Grafana monitoring fallback	16500x
6	Retention enable after 30+ day soak	≥17000x
7	PR #669 merge / Nuxt deploy	external (different clone)
8	Auto-instantiate from event (template.published → spawn instance)	17500x
9	Template piece mutation invariants (supersede propagation)	16000x
10	Cross-template piece sharing observability	16000x

What 15000x intentionally did NOT do

• Did NOT add a new healthcheck surface — 8 is the right size; productization observable through catalog count + vector boundary + write gates + 2 new views.
• Did NOT create a "template" event_type — would require event_outbox CHECK update (10000x defect lesson); iu.collection_created already fires.
• Did NOT touch the 12000x untracked ops dir — left as-is per origin macro's intent.
• Did NOT introduce template_status workflow — lifecycle_status on iu_piece_collection already covers it.