fix(fixtures): pin pattern.id to detector consts (audit #421)

[trilamsr]

Summary

Audit issue #421 finding-2 root-fix. PR #398 landed the canonical v1.0-rc1 SDK fixture at docs/schemas/fixtures/shipped-patterns-v1.0.0-rc1.json with five rows carrying wrong pattern.id values — the fixture was hand-typed by sequential counter (..14, 15, 16, 17, 18, 19, 20, 21) instead of being copied from the PatternID* constants in module/pkg/patterns/*.go. The envelope schema only constrains pattern.id to type:string, minLength:1, so per-pattern envelope tests round-tripped the drift silently.

Before / after pattern.id

fixture row	before	canonical (module/pkg/patterns/*.go)
hbm_ecc	"17"	PatternIDHBMECC = "3"
thermal_throttle	"18"	PatternIDThermalThrottle = "4"
pcie_aer	"19"	PatternIDPCIeAER = "5"
cuda_oom	"20"	PatternIDCUDAOOM = "10"
ib_link_flap	"21"	PatternIDIBLinkFlap = "2"

pod_evicted ("14"), nccl_hang ("15"), xid_correlation ("16"), silent_data_corruption ("13") were already correct.

Scoped-keys delta

The ib_link_flap row also used unscoped "node" while IBLinkFlapVerdict.Node serializes as "k8s.node.name" (customer-stable namespace per docs/ATTRIBUTES.md line 152-154 + docs/patterns/pattern-2-ib-link-flap.md). Renamed in the fixture to mirror what the Go struct actually emits. The other unscoped keys on this row (hca_device, port, transition_count) match the Go struct's json:"..." tags as-is — those are the envelope key names; the operator-facing dashboard scoped names (tracecore.alert.ib_link_flap.transition_count, hw.network.ib.device, hw.network.ib.port.num) are the OTel log-record attributes the processor promotes alongside the JSON payload, a separate surface.

Drift-prevention test

TestCanonicalShippedFixtures_PatternIDsMatchDetectorConsts in module/pkg/patterns/verdict_envelope_schema_test.go pins each fixture row's pattern.id to the PatternID* const in the detector package and asserts symmetry (every const has a fixture, every fixture matches a const). Confirmed RED with the buggy fixture (5 failures matching the audit prediction exactly), GREEN after the fix.

Correct `pattern.id` values for five rows in the v1.0-rc1 canonical SDK fixture and add a drift-prevention test pinning fixtures to detector-package constants.

Refs #421
Refs #398

Test plan

• go test ./pkg/patterns/... PASS (new test + existing envelope suite)
• go test ./sdk/verdict/... PASS (Go SDK round-trip)
• python3 -m pytest python/tracecore_verdict/test_decode.py 22/22 PASS
• make vet clean
• make lint 0 issues
• RED→GREEN cycle confirmed on TestCanonicalShippedFixtures_PatternIDsMatchDetectorConsts

[trilamsr]

Review: SHIP

Dual-surface verification: PASSED

• transition_count unscoped in JSON envelope (ib_link_flap.go:121 json:\"transition_count\")
• Promoted as scoped tracecore.alert.ib_link_flap.transition_count in OTel log-record attributes (ATTRIBUTES.md)
• All other envelope keys (hca_device, port, k8s.node.name) match struct tags correctly

Pattern.id corrections: All 5 match detector consts:

• hbm_ecc "17" → "3" ✓ (PatternIDHBMECC)
• thermal_throttle "18" → "4" ✓ (PatternIDThermalThrottle)
• pcie_aer "19" → "5" ✓ (PatternIDPCIeAER)
• cuda_oom "20" → "10" ✓ (PatternIDCUDAOOM)
• ib_link_flap "21" → "2" ✓ (PatternIDIBLinkFlap)

Test coverage: LOAD-BEARING

• TestCanonicalShippedFixtures_PatternIDsMatchDetectorConsts passes all 9 fixture rows + 1 detector const
• Symmetry guard catches orphans (fixtures without consts, consts without fixtures)
• Mutation test confirms: mutating fixture pattern.id fails the test before SDK round-trip silently swallows drift
• All existing tests PASS (patterns + Go SDK + Python SDK 22/22)

Scoped-key audit: node → k8s.node.name is correct per docs/patterns/02-ib-link-flap.md; other unscoped keys are envelope-surface intentional.

No findings. Ready to merge.