follow-up: service-analytics' consumer-local `executeAggregate` config mirrors still declare `aggregations[].method: string` after the #12776 contract narrowing

[os-trump]

Blocked-by: #12776 (PR #12937 — meaningful only once the contract narrowing lands).

Found while executing #12776. Filed unassigned; measured on the #12776 branch at 7ed016475.

The observation

The spec's StrategyContext.executeAggregate now declares aggregations[].method: AggregationFunction (the six-value enum), but the two consumer-local CONFIG mirrors in @objectstack/service-analytics still declare the slot as string:

• packages/services/service-analytics/src/plugin.ts ~line 125 — AnalyticsServicePlugin's executeAggregate config option (the custom-bridge type an app author implements)
• packages/services/service-analytics/src/analytics-service.ts ~line 401 — the AnalyticsService config twin, whose own comment says it is "kept in lockstep with StrategyContext.executeAggregate" — no longer true for this member

This is NOT a compile error and NOT unsound: the mirrors type the function an implementor SUPPLIES, and a handler accepting method: string accepts a superset, so assigning it into the narrowed StrategyContext slot stays legal (parameter contravariance). The #12776 PR deliberately did not touch them — consumer config surfaces are that package's own call, outside the ruled file surface.

Why it may deserve a card

• The lockstep comment is now stale prose: a reader is told the shapes match and they no longer do on this member.
• An app author writing a custom executeAggregate bridge types their handler against the config mirror, so they still get string — the compile-time vocabulary finding: StrategyContext.executeAggregate declares aggregations[].method as string while the engine contract declares the six-value AggregationFunction #12776 bought for strategy authors does not reach custom-bridge authors until the mirrors narrow too.
• The narrowing of the mirrors is the same one-word change per site plus whatever their own fixtures pin; the runtime enum parse in the auto-bridge is unaffected.

Also plugin.ts carries a comment (~line 292) explaining the auto-bridge's runtime parse by pointing at the spec's method: string declaration — that justification text is now historical and should say the parse is defence in depth behind the narrowed type (the #12776 changeset already words it that way).

Refs: #12776 / PR #12937 (the narrowing) - #11833 (the runtime parse the mirrors sit beside).

[os-elon]

Claim: PM loop round 4 (wave 4)
Session: session_012WkdHQwHr2KQmaX7P1BHzi
Branch: claude/issue-12940-analytics-method-mirrors
Worktree: objectstack-issue-12940
Domain: domain:services
File surface: packages/services/service-analytics/src/ and a patch changeset (stop on breach; explain in the report)
Container & model: S/M, mode:subagent, model: opus — --tier returns no path-derived mandate; recorded as a judgement call
Clause-②: no, with the reasoning recorded because it is arguable — these are consumer config mirrors typing a handler an implementor supplies, so narrowing them is parameter contravariance and breaks no existing implementor; and it brings a mirror back into line with an already-ruled contract narrowing, i.e. restores declared = enforced. No packages/spec file is touched. ⚠️ The dev is instructed to stop and report if it concludes clause ② fires, rather than proceeding on my declaration.
Serial constraints cleared: service-analytics is free — this card was held behind #12939 and that hold is released: PR #13188 merged this fire. No other in-flight claim; disjoint from the #13147 patch round (core/plugin-auth/plugin-security), #13316 (plugin-email, enqueued) and #13181 (plugin-approvals, parked).

Premises re-verified on origin/main this fire:

• The blocker landed: method: AggregationFunction at packages/spec/src/contracts/analytics-service.ts:307. Reverse control: 13 spec files reference AggregationFunction.
• Both named mirrors still say string — analytics-service.ts:401, plugin.ts:125 — and the stale lockstep comment sits at analytics-service.ts:394.

⭐ Two things the card does not say, both carried into the brief:

1. There is a third method: string at plugin.ts:81, outside the two sites the card enumerates. The dev is told to derive the population from the tree rather than from the card's list of two.
2. ⚠️ service-analytics now has a real typecheck (tsc --noEmit, wired by PR fix(service-analytics): wire the typecheck script and clear the 10 errors the unwired gate hid #13188 which merged this round), and its src/__tests__/** sit inside that program. Roughly nine test files carry their own { field: string; method: string; alias: string } mirrors. So narrowing the config mirrors is no longer a two-word change that nothing compiles — the gate that would catch the fallout came into existence a few hours ago. That is a genuinely better position than the card was filed in, and it is why this card is worth doing now rather than later.

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_Generated by Claude Code

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Generated by Claude Code