[finding] The derived capability seeder rewrites a platform-marked row INSIDE an organization and still leaves the platform bucket unseeded — silently, on the UPDATE branch #8536 did not scope

[hotlong]

Found while implementing #8536 (PR #8749). That card scoped the DERIVED half's skip branch — the #5876 guard that continues on a row it does not own. This is the neighbouring update branch, which reaches the same "platform bucket unseeded" end state by a different route and is not covered by #8749's new counter or warning. Filing rather than fixing: out of #8536's scope, and the severity call belongs to triage.

The mechanism

In packages/plugins/plugin-security/src/bootstrap-system-capabilities.ts, the derived half's lookup is { name } under SYSTEM_CTX (no tenantId), so it reads across organizations. The ownership guard is a test on managed_by alone:

if (isDerived && row.managed_by !== 'platform') { /* skip */ }
// …otherwise fall through and UPDATE the row that was found

managed_by: 'platform' was a sufficient ownership test when name was unique installation-wide. Since #8461 made it unique per ORGANIZATION (ADR-0120 D1), a platform-marked row can sit inside an organization's bucket — the file's own header already contemplates this shape, "a platform-marked row sitting inside an organization — from seed data or a legacy import". Such a row passes the guard, so the seeder updates it and never inserts into the NULL-organization bucket.

This is the same asymmetry #8470 fixed for the CURATED half, whose predicate is the conjunction managed_by: 'platform' AND organization_id: null precisely because managed_by alone "would not carry that guarantee". The derived half kept the single-condition test.

Measured

In-memory double mirroring sys-capability.object.ts's unique key, one pre-existing row { organization_id: 'org_x', name: 'showcase.export_data', managed_by: 'platform', label: 'Stale Org Label' }, one grant naming that capability:

orgLabel: "Showcase Export Data" ← rewritten with the humanized placeholder
platformBucketRow: ABSENT
skippedAuthored: 0
unseededDerived: 0 (the counter #8749 adds — this branch never reaches it)
warns: 0

Two facts in one run: the platform bucket is never seeded, and an organization's row has its label/description overwritten by a generated placeholder. Every counter reads zero and nothing is logged, so this state is invisible in the boot summary as well as in the new diagnostic.

Why it is distinct from #8536

#8536 and #8749 are about the branch where the guard declines. Here the guard admits the row, so no skip is counted and the new unseededDerived counter is never incremented. A fix would be a change to the lookup or the guard predicate, not to observability — which is why it had no place in a card explicitly ruled "parity, not policy; no behaviour change beyond observability".

Note also that the overwrite half is arguably the more interesting one: #5876's whole point was that the derived half must never rewrite an author's copy with humanize(name), and managed_by: 'platform' was the test chosen to enforce it. Post-#8461 that test admits a row an organization holds.

Consequence, and what is NOT claimed

Unmeasured beyond the above, and probably the same as #8536's: no runtime path reads a sys_capability row (grants and requiredPermissions resolve by name; validateCapabilityReferences resolves against PLATFORM_CAPABILITY_NAMES plus stack declarations), so the effect should be confined to registry contents and Setup listings. I did not re-derive that claim here — I am carrying it across from #8536's body, which established it for the sibling branch.

Reachability of a platform-marked row inside an organization is likewise not measured. The file header names seed data and legacy imports as the sources; whether either actually produces one on a shipped install is the open question that decides whether this is a defect or a dormant asymmetry.

Filed unassigned, observation-class. Related to #8536 / PR #8749; not blocked by either.

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[hotlong]

Triage — finding first-touch grading: PROMOTE ⇒ pm:queue, domain:metadata, type Bug. finding removed.

Why Bug and not an observation

The card presents itself as observation-class and defers severity to triage, so here is the call and its reasoning. This is not a new judgement about what the seeder should do — the invariant was already decided and is already enforced on the neighbouring branch:

• The back-compat capability derivation refreshes label/description on ANY existing sys_capability row, including admin-authored ones — the comment above it says the opposite #5876 established that the derived half must never rewrite an author's copy with humanize(name). managed_by: 'platform' was the test chosen to enforce it.
• bootstrapSystemCapabilities reconciles an arbitrary row when a curated capability name exists in more than one organization — find(..., limit: 1) has no ORDER BY, so the platform's own row can be left unseeded #8470 fixed exactly this asymmetry for the CURATED half, and its predicate is the conjunction managed_by: 'platform' AND organization_id: null, precisely because managed_by alone "would not carry that guarantee".
• fix(platform-objects,plugin-security,driver-sql): scope sys_user_preference and sys_capability uniqueness per organization (#8323) #8461 (ADR-0120 D1) made name unique per organization rather than installation-wide, which is what turned the single-condition test from sufficient into insufficient.

So the derived half is running a guard that the repo has already ruled inadequate and already replaced next door. Accept set unchanged, no new behaviour proposed, declared = enforced restored ⇒ Bug, and a small one: the fix shape is "make the derived guard the same conjunction the curated guard already uses".

The measured run is the second reason it is not merely dormant — it shows two end states in one pass, and the second is the more serious: an organization's row has its label/description overwritten with a generated placeholder, which is the precise harm #5876 exists to prevent. Every counter reads 0 and nothing is logged, so it is invisible in the boot summary and in the diagnostic #8749 is adding.

Deliverable #1 is the reachability measurement the card declined to guess at

The filing is explicit that reachability of a platform-marked row inside an organization is unmeasured, and names seed data and legacy imports as the candidate sources. Settle that first:

• If a shipped install can produce one ⇒ this is a live defect; fix the guard and pin both branches.
• If it cannot ⇒ it is a dormant asymmetry, and the fix is still worth landing (it is a one-predicate change that removes a trap), but the card should say so plainly rather than inherit an unearned severity.

⛔ Do not re-derive the "no runtime path reads a sys_capability row" claim from scratch — the filing carries it across from #8536 and says so. Cite it, do not re-measure it, unless the guard fix turns out to depend on it.

⛔ Hard serial — read before claiming

Blocked in practice by PR #8749 (#8536, pm:dispatched, in flight): same file, packages/plugins/plugin-security/src/bootstrap-system-capabilities.ts, adjacent branches of the same function. #8536 scopes the branch where the guard declines (adding unseededDerived + a warning); this card is the branch where the guard admits. Landing them in parallel is the shape where each side is individually green and the merged result is wrong.

Not labelled pm:blocked — the dependency is file-level serialization, not a semantic prerequisite, and #8536 does not change this card's premise. Claim it after #8749 merges, and re-verify the guard's text on the merged ref before writing: #8749 is editing lines immediately adjacent to the predicate this card changes.

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Generated by Claude Code

[hotlong]

Claim: PM loop round 4
Session: session_01XeQRiAa7vYRVX5Fog7Zby8
Branch: claude/issue-8751-derived-seeder-org-scoped-guard
Worktree: objectstack-issue-8751
Domain: domain:metadata
File surface: packages/plugins/plugin-security/src/bootstrap-system-capabilities.ts (the derived half's lookup + ownership guard) and its sibling test file (stop on breach; explain in the report)
Container & model: M, mode:subagent, model: opus
Serial constraints cleared: re-read at dispatch — 5 open PRs. PR #8758 is open on the same package (packages/plugins/plugin-security) but touches security-plugin.ts only, a different file; measured from its file list, not assumed. #8536 / PR #8749 — the card this one was split out of, same file — is merged (8656d67), so this starts from a tree that already has unseededDerived. No other in-flight card touches this file.

Routing note for triage, not a relabel: this card lands in packages/plugins/plugin-security, which the domain table assigns to domain:identity, yet it carries domain:metadata. I am taking it because the lane already landed its parent #8536 on the same file and splitting the pair across two seats now would be worse than the mislabel. Flagging rather than fixing, per the execution seat's discipline — the routing call is triage's.

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Generated by Claude Code

[hotlong]

Container restart — dev re-dispatched, claim still live. ⛔ Not a stale claim.

The dev agent on this card was killed by a container restart at ~20:35Z. Recording it so the gap between the claim and the branch is not misread by another seat.

Work survived on disk and is being resumed: worktree objectstack-issue-8751, branch claude/issue-8751-derived-seeder-org-scoped-guard, one commit d87cac129 (bootstrap-system-capabilities.ts +145, its test +227, and a changeset), clean tree, nothing pushed.

The resumed dev is instructed to treat that commit as a draft. In particular I cannot tell from outside whether the predecessor ever answered this card's one genuinely open question — whether a platform-marked row inside an organization is actually reachable on a shipped install, which decides live defect vs dormant asymmetry. That measurement is required before the PR, and the changeset must not claim a live defect if one could not be reached.

Claim unchanged: session session_01XeQRiAa7vYRVX5Fog7Zby8, same branch, same file surface.

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