Enhance security, performance, and implement failure management features

[debdevops]

What does this PR do?

Type of change

• Bug fix
• New feature
• Documentation
• Refactor / cleanup
• Other (describe above)

Checklist

• dotnet build services/api/ServiceHub.sln --configuration Release passes with zero warnings
• npm run -w apps/web build passes with zero warnings
• Backend unit/integration tests pass (dotnet test)
• Frontend tests pass (npm run -w apps/web test)
• New/changed behavior has test coverage
• No secrets, connection strings, or credentials added to source or logs
• Docs updated if user-facing behavior changed (README, CHANGELOG, or docs/)

Screenshots (UI changes only)

[Copilot]

Pull request overview

This PR expands “Failure Signature Intelligence” across backend + frontend by adding signature lifecycle state, operational knowledge version history, and a cancellable “signature replay” job flow, along with UI pages to browse and manage signatures.

Changes:

• Add signature lifecycle tracking (Active/Resolved/Reopened/Suppressed/Archived) and trend labeling (“New/Recurring/Escalating”).
• Add operational knowledge editing enhancements: UpdatedBy plus persisted knowledge version history and history API.
• Add signature replay preview/start + job polling/cancellation endpoints and corresponding UI hooks/pages/components.

Reviewed changes

Copilot reviewed 76 out of 135 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
services/api/tests/ServiceHub.UnitTests/Shared/Helpers/SignatureTrendHeuristicTests.cs	Adds unit tests for signature trend heuristic labels.
services/api/tests/ServiceHub.UnitTests/Infrastructure/SignatureReplay/SignatureReplayExecutorTests.cs	Adds executor tests for replay success/failure/skip/cancel scenarios.
services/api/tests/ServiceHub.UnitTests/Infrastructure/SignatureLifecycleServiceTests.cs	Adds tests for lifecycle transitions, isolation, and batching.
services/api/tests/ServiceHub.UnitTests/Infrastructure/NamespaceSignatureLookupServiceTests.cs	Adds tests for new GetByHashAsync read-only lookup.
services/api/tests/ServiceHub.UnitTests/FailureKnowledgeServiceTests.cs	Updates tests for knowledge updates, UpdatedBy, and history snapshots.
services/api/tests/ServiceHub.UnitTests/Core/DTOs/UpsertKnowledgeRequestValidationTests.cs	Adds validation tests for new upsert knowledge request DTO.
services/api/tests/ServiceHub.UnitTests/Api/Controllers/V1/SignatureReplayControllerTests.cs	Adds controller tests for intent headers + job endpoints.
services/api/src/ServiceHub.Shared/Helpers/SignatureTrendHeuristic.cs	Introduces deterministic “trend” heuristic computation.
services/api/src/ServiceHub.Shared/Constants/ApiRoutes.cs	Adds routes for signature detail/timeline/status/knowledge/history/replay + job polling.
services/api/src/ServiceHub.Infrastructure/SignatureReplay/SignatureReplayJobStore.cs	Implements in-memory job storage + cancellation.
services/api/src/ServiceHub.Infrastructure/SignatureReplay/SignatureReplayExecutor.cs	Implements sequential replay execution with progress + failure sampling.
services/api/src/ServiceHub.Infrastructure/SignatureLifecycleService.cs	Adds in-memory lifecycle state store + transition validation.
services/api/src/ServiceHub.Infrastructure/Persistence/Migrations/DlqDbContextModelSnapshot.cs	Updates EF snapshot for knowledge UpdatedBy + new history table.
services/api/src/ServiceHub.Infrastructure/Persistence/Migrations/20260802145305_AddFailureKnowledgeHistory.cs	Adds migration for FailureKnowledgeHistory + UpdatedBy column.
services/api/src/ServiceHub.Infrastructure/Persistence/DlqDbContext.cs	Registers FailureKnowledgeHistory entity mapping + UpdatedBy constraints.
services/api/src/ServiceHub.Infrastructure/NamespaceSignatureLookupService.cs	Adds read-only GetByHashAsync implementation.
services/api/src/ServiceHub.Infrastructure/FailureKnowledgeService.cs	Adds knowledge history snapshotting + history retrieval; adds UpdatedBy.
services/api/src/ServiceHub.Infrastructure/DlqHistoryService.cs	Adds GetByIdsAsync multi-fetch helper for signature-related messages.
services/api/src/ServiceHub.Infrastructure/DependencyInjection.cs	Wires new services (lifecycle singleton, signature replay services/job store).
services/api/src/ServiceHub.Infrastructure/BulkOperations/BulkOperationExecutor.cs	Exposes entity/subscription resolver for signature replay reuse.
services/api/src/ServiceHub.Core/Models/SignatureLifecycle.cs	Adds lifecycle snapshot + event models.
services/api/src/ServiceHub.Core/Models/FailureKnowledgeHistoryEntry.cs	Adds API-facing model for knowledge version history entries.
services/api/src/ServiceHub.Core/Models/FailureKnowledge.cs	Extends knowledge model with optional UpdatedBy.
services/api/src/ServiceHub.Core/Interfaces/ISignatureReplayService.cs	Adds interface for preview/start/get/cancel signature replay jobs.
services/api/src/ServiceHub.Core/Interfaces/ISignatureReplayJobStore.cs	Adds in-memory job store contract + mutable job state model.
services/api/src/ServiceHub.Core/Interfaces/ISignatureReplayExecutor.cs	Adds executor contract for background job processing.
services/api/src/ServiceHub.Core/Interfaces/ISignatureLifecycleService.cs	Adds lifecycle service contract.
services/api/src/ServiceHub.Core/Interfaces/INamespaceSignatureLookupService.cs	Adds GetByHashAsync to read signatures without mutating counts/timestamps.
services/api/src/ServiceHub.Core/Interfaces/IFailureKnowledgeService.cs	Adds knowledge history retrieval API.
services/api/src/ServiceHub.Core/Interfaces/IDlqHistoryService.cs	Adds GetByIdsAsync contract for resolving related messages.
services/api/src/ServiceHub.Core/Enums/SignatureLifecycleStatus.cs	Introduces lifecycle status enum.
services/api/src/ServiceHub.Core/Entities/FailureKnowledgeHistoryEntity.cs	Adds EF entity for persisted knowledge version snapshots.
services/api/src/ServiceHub.Core/Entities/FailureKnowledgeEntity.cs	Adds UpdatedBy and updates tags delimiter documentation.
services/api/src/ServiceHub.Core/DTOs/Responses/DlqSignatureResponses.cs	Expands signature responses; adds knowledge history + lifecycle response shapes.
services/api/src/ServiceHub.Core/DTOs/Responses/DlqResponses.cs	Adds string-length validation for notes fields.
services/api/src/ServiceHub.Core/DTOs/Requests/UpsertKnowledgeRequest.cs	Adds request DTO with validation annotations.
services/api/src/ServiceHub.Core/DTOs/Requests/SignatureReplayRequests.cs	Adds request DTOs for signature replay preview/start scopes.
services/api/src/ServiceHub.Core/DTOs/Requests/MarkForReviewRequest.cs	Adds request DTO for knowledge review due date.
services/api/src/ServiceHub.Api/wwwroot/index.html	Updates referenced hashed asset filenames.
services/api/src/ServiceHub.Api/wwwroot/assets/useSubscriptions-Baw_o8yr.js	Updates bundled subscription hook asset references.
services/api/src/ServiceHub.Api/wwwroot/assets/useMessages-CEj5z1Fk.js	Adds new bundled messages hook asset.
services/api/src/ServiceHub.Api/wwwroot/assets/useMessages-BSnAvIl-.js	Removes old bundled messages hook asset.
services/api/src/ServiceHub.Api/wwwroot/assets/useHealth-D9C9NyDC.js	Updates bundled health hook asset references.
services/api/src/ServiceHub.Api/wwwroot/assets/SignatureListPage-JU7m1UD8.js	Adds bundled signatures list page asset.
services/api/src/ServiceHub.Api/wwwroot/assets/SignatureDetailsPage-DaHdqddp.js	Adds bundled signature details page asset.
services/api/src/ServiceHub.Api/wwwroot/assets/CopyButton-CjfK2dyd.js	Removes old bundled copy button asset.
services/api/src/ServiceHub.Api/wwwroot/assets/CopyButton-BlTwaWwU.js	Adds new bundled copy button asset.
services/api/src/ServiceHub.Api/wwwroot/assets/ConfirmDialog-6QYJwtdw.js	Updates bundled confirm dialog asset references.
services/api/src/ServiceHub.Api/Security/IntentHeaders.cs	Adds explicit intent value for signature replay.
services/api/src/ServiceHub.Api/Controllers/V1/SignatureReplayController.cs	Adds replay preview/start + job get/cancel endpoints with intent guard + audit logs.
services/api/README.md	Updates Docker section heading.
SECURITY.md	Replaces “Unreleased” entry with versioned release entry.
README.md	Updates product roadmap copy to include Failure Signature Intelligence.
packages/servicehub-ui-shared/src/lib/api/signatureReplay.ts	Adds UI-shared client for signature replay endpoints + types.
packages/servicehub-ui-shared/src/lib/api/intentHeaders.ts	Adds signature:replay intent header constant.
packages/servicehub-ui-shared/src/lib/api/dlqSignatures.ts	Expands DLQ signatures API/types: detail/timeline/status/knowledge/history.
packages/servicehub-ui-shared/src/hooks/useSignatureReplay.ts	Adds React Query hooks for preview/start/poll/cancel signature replay jobs.
packages/servicehub-ui-shared/src/tests/lib/api/signatureReplay.test.ts	Adds unit tests for signature replay API client mapping + headers.
packages/servicehub-ui-shared/src/tests/lib/api/dlqSignatures.test.ts	Updates/extends tests for expanded signatures API methods.
packages/servicehub-ui-shared/src/tests/hooks/useSignatureReplay.test.tsx	Adds tests for signature replay hooks (polling/invalidation/cancel).
apps/web/src/router.tsx	Adds routes for signature list + signature details pages.
apps/web/src/pages/SignatureDetailsPage.tsx	Adds signature details UI page (timeline, lifecycle actions, replay, related msgs).
apps/web/src/pages/DlqHistoryPage.tsx	Minor UI copy update (“Clear filters”).
apps/web/src/pages/ConnectPage.tsx	Improves form accessibility via htmlFor + id wiring.
apps/web/src/pages/AuditPage.tsx	Improves accessibility/keyboard interaction for audit list + clear search aria label.
apps/web/src/components/messages/RefreshIndicator.tsx	Removes refresh indicator component.
apps/web/src/components/layout/Footer.tsx	Switches Help link to client-side route.
apps/web/src/components/fab/MessageSendFAB.tsx	Removes old mock FAB implementation.
apps/web/src/components/fab/index.ts	Updates FAB exports after removals.
apps/web/src/components/dlq/StatusBadge.tsx	Adds lifecycle status styles and introduces TrendBadge.
apps/web/src/components/dlq/SignatureTimelinePanel.tsx	Adds UI timeline rendering for signature timeline events.
apps/web/src/components/dlq/SignatureReplayProgressPanel.tsx	Adds floating progress card for signature replay jobs.
apps/web/src/components/dlq/SignatureLifecycleActions.tsx	Adds lifecycle transition action buttons (client-side matrix mirror).
apps/web/src/components/dlq/KnowledgeHistoryPanel.tsx	Adds UI panel for viewing knowledge version history.
apps/web/src/components/dlq/index.ts	Exports new signature-related DLQ components.
apps/web/src/components/dlq/DlqSignaturesPanel.tsx	Adds “View details” link + passes namespace to investigation panel.
apps/web/src/components/ai/AIFindingsDropdown.tsx	Improves responsiveness via max-width constraint.
apps/web/src/tests/pages/SignatureListPage.test.tsx	Adds unit tests for signatures list page filtering/rendering.
apps/web/src/tests/pages/SignatureDetailsPage.test.tsx	Adds unit tests for signature details page behavior + replay flow.
apps/web/src/tests/components/messages/RefreshIndicator.test.tsx	Removes tests for removed refresh indicator component.
apps/web/src/tests/components/dlq/StatusBadge.test.tsx	Updates tests for new statuses and TrendBadge.
apps/web/src/tests/components/dlq/SignatureTimelinePanel.test.tsx	Adds tests for timeline panel rendering + details chips.
apps/web/src/tests/components/dlq/SignatureReplayProgressPanel.test.tsx	Adds tests for replay progress panel behavior.
apps/web/src/tests/components/dlq/SignatureReplayPreviewModal.test.tsx	Adds tests for replay preview modal behavior.
apps/web/src/tests/components/dlq/SignatureLifecycleActions.test.tsx	Adds tests for lifecycle actions visibility/behavior.
apps/web/src/tests/components/dlq/KnowledgeHistoryPanel.test.tsx	Adds tests for knowledge history UI (demo mode/loading/empty/data).
apps/web/src/tests/components/dlq/KnowledgeEditDialog.test.tsx	Adds tests for knowledge editor dialog validation/submit/demo-mode.
apps/web/src/tests/components/dlq/DlqSignaturesPanel.test.tsx	Updates tests for details link + router wrapping.
apps/web/README.md	Updates docs for new pages and refreshes last-updated text.

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