[WIP] feat: Audit missing item for node intergration GetJudgement / Broadcast / Collect Result

[HanaYukii]

Summary

Implement GetJudgement — the function that lets an auditor verify whether a work-report is honest (GP §17.16–17.17).

How it works:

1. Fetch the original work-package bundle from the guarantor who made the claim
2. Re-run the computation using the same PVM pipeline the guarantor used
3. Compare the result — if it matches, the report is valid; otherwise it's invalid

The PVM execution pipeline is already in place (WorkPackageController.Process()). The missing piece is the networking layer to actually fetch bundles from other nodes, so a stub is used for now. All places that need node-layer wiring are marked with NODE-TODO.

What changed:

File	What
fetch_bundle.go	New — BundleFetcher interface + stub placeholder
judgement.go	New — GetJudgement logic (fetch → re-execute → compare)
auditing.go	Updated — added NODE-TODO annotations with integration guidance
work_package.go	Updated — exported ComputeErasureRoot for bundle verification

---

Node-Side TODOs

All tagged NODE-TODO in code. Ref branch: feat/jam-np-ce-handler

Priority	Tag	What node layer needs to do
🔴 P0	[bundle fetch]	Implement BundleFetcher interface (replace StubBundleFetcher in fetch_bundle.go). Fast path: request bundle from guarantor peers via CE using ReportGuarantee.Signatures[].ValidatorIndex. Verify with work_package.ComputeErasureRoot(). Slow path: reconstruct from ≥342 erasure-coded chunks.
🟡 P1	[CE144 send]	BroadcastAnnouncement() — send audit announcement + VRF evidence to all validators
🟡 P1	[CE144 recv/sync]	UpdateAssignmentMapFromOtherNode() + SyncAssignmentMapFromOtherNodes() — background recv writes to buffer, sync drains buffer per tranche to count no-shows
🟡 P1	[CE145 send]	BroadcastAuditReport() — send signed judgment (validity + signature) to all validators
🟡 P1	[CE145 recv/sync]	UpdatePositiveJudgersFromOtherNode() + SyncPositiveJudgersFromOtherNodes() — same buffer/drain pattern, feeds into next tranche's ComputeAnForValidator()
🟡 P1	[tranche sync flow]	Define how CE144/CE145 recv handlers push to a shared buffer (channel or mutex-guarded map), and how Sync functions drain it. See SingleNodeAuditingAndPublish() Steps 9/16 for call sites.
🟢 P2	[timer]	WaitNextTranche() — sleep until slotStart + (tranche+1) * 8s (GP §17.7)

---

Files changed:

File	Change
judgement.go	New — core GetJudgement logic
fetch_bundle.go	New — BundleFetcher interface + stub
auditing.go	Update — clearer code, add NODE-TODO comments
iwork_package.go	Update — export ComputeErasureRoot

---

How GetJudgement works

GetJudgement(auditReport)
│
├─ Step A: DefaultBundleFetcher.FetchBundle(report)
│ → fetch raw bundle bytes from guarantor (CE) or erasure reconstruction
│
├─ Step B: work_package.NewSharedController(bundleBytes, coreIndex).Process()
│ → decode bundle → ΨI (is-authorized) → ΨR per work-item → assemble WorkReport
│ → all PVM infrastructure already in place
│
└─ Step C: workReportsEqual(recomputed, original)
→ canonical serialization (WorkReportSerialization) + bytes.Equal

Node-Side Integration TODOs Details

Bundle Fetching

Tag	Function	CE	What node layer needs to provide
NODE-TODO [bundle fetch]	StubBundleFetcher.FetchBundle()	Bundle Request CE	Replace stub with real impl: request full bundle from guarantor peers (identified via ReportGuarantee.Signatures[].ValidatorIndex), verify against PackageSpec.ErasureRoot using work_package.ComputeErasureRoot(). Fallback: reconstruct from ≥342 erasure-coded chunks.

Audit Announcement (CE144)

Tag	Function	Direction	What node layer needs to provide
NODE-TODO [CE144 send]	BroadcastAnnouncement()	Send	Broadcast audit announcement + VRF evidence to all validators. Ref: ce144.go — HandleAuditAnnouncement_Send
NODE-TODO [CE144 recv]	UpdateAssignmentMapFromOtherNode()	Recv	On CE144 message arrival, merge into local assignment map. Ref: ce144.go — HandleAuditAnnouncement_Recv
NODE-TODO [CE144 sync]	SyncAssignmentMapFromOtherNodes()	Sync	Collect all CE144 announcements received so far per tranche, determines no-show count. Ref: ce144.go — GetAllAuditAnnouncementsForHeader

Judgment Publication (CE145)

Tag	Function	Direction	What node layer needs to provide
NODE-TODO [CE145 send]	BroadcastAuditReport()	Send	Broadcast signed judgment (validity + signature) to all validators. Ref: ce145.go — HandleJudgmentAnnouncement_Auditor
NODE-TODO [CE145 recv]	UpdatePositiveJudgersFromOtherNode()	Recv	On CE145 message arrival, merge into local positive-judger map. Ref: ce145.go — HandleJudgmentAnnouncement_Validator
NODE-TODO [CE145 sync]	SyncPositiveJudgersFromOtherNodes()	Sync	Collect all CE145 judgments received so far per tranche. Ref: ce145.go — GetAllJudgmentsForWorkReport

Timer

Tag	Function	What node layer needs to provide
NODE-TODO [timer]	WaitNextTranche()	Timer/event mechanism: each tranche = A (8 seconds) after slot start (GP §17.7)

---

[HanaYukii]

This PR listed the requirement of node side todo work for the auditing part, please help to check the discribtion and code.

@Terryhung FYI.