diff --git a/.github/ISSUE_TEMPLATE/bug_report.md b/.github/ISSUE_TEMPLATE/bug_report.md
index 524bab5..f597884 100644
--- a/.github/ISSUE_TEMPLATE/bug_report.md
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -30,5 +30,17 @@ What actually happened.
 ## Logs / Screenshots
 Paste logs or screenshots that help explain the issue.
 
+## Acceptance Criteria
+- [ ] Root cause identified.
+- [ ] Fix validated in local or CI environment.
+- [ ] No regression introduced for related paths.
+
+## Validation Steps
+List exact commands or manual steps used to verify the fix.
+```bash
+# example:
+# dotnet test ...
+```
+
 ## Additional Context
 Any additional information that may help.
diff --git a/.github/ISSUE_TEMPLATE/feature_request.md b/.github/ISSUE_TEMPLATE/feature_request.md
index 7e3dfad..82a7fd0 100644
--- a/.github/ISSUE_TEMPLATE/feature_request.md
+++ b/.github/ISSUE_TEMPLATE/feature_request.md
@@ -15,5 +15,17 @@ Describe the change or feature you would like to see.
 ## Alternatives Considered
 Any alternative solutions or workarounds you have considered.
 
+## Acceptance Criteria
+- [ ] Clear, testable success criteria are defined.
+- [ ] Backward compatibility impact is assessed.
+- [ ] Documentation impact is assessed.
+
+## Validation Steps
+List the tests/checks that prove the feature works as intended.
+```bash
+# example:
+# npm run build
+```
+
 ## Additional Context
 Add any additional context, mockups, or screenshots here.
diff --git a/.github/ISSUE_TEMPLATE/task.md b/.github/ISSUE_TEMPLATE/task.md
new file mode 100644
index 0000000..9782af8
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/task.md
@@ -0,0 +1,29 @@
+---
+name: Task
+about: Track scoped implementation work
+title: "[Task] "
+labels: todo
+assignees: ""
+---
+
+## Summary
+Describe the task in one or two sentences.
+
+## Scope
+- In scope:
+- Out of scope:
+
+## Acceptance Criteria
+- [ ] Criteria 1
+- [ ] Criteria 2
+- [ ] Criteria 3
+
+## Validation Steps
+List exact checks for completion.
+```bash
+# example:
+# dotnet build ...
+```
+
+## Dependencies / Related Issues
+Link dependencies and related tickets (e.g. `Epic: #<id>`).
diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index d1ab05d..6183c48 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -6,6 +6,18 @@ For v2.3 release-track PRs, you can use:
 ## Summary
 Describe the changes and their purpose.
 
+## Linked Issue
+Closes #<issue-id>
+
+## Validation
+- Commands/tests run:
+```bash
+# paste exact validation commands and key outcomes
+```
+
+## Rollback Notes
+Describe rollback plan or why rollback is low risk.
+
 ## Testing
 - [ ] Tests added/updated
 - [ ] Tests run locally
@@ -13,8 +25,6 @@ Describe the changes and their purpose.
 ## Checklist
 - [ ] Code style and formatting checked
 - [ ] Documentation updated (if applicable)
+- [ ] Security impact reviewed (auth/secrets/supply-chain)
 - [ ] No secrets or credentials committed
 - [ ] Breaking changes documented
-
-## Related Issues
-Link to issues or discussions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8bc37cc..9684a17 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@ Semantic Versioning.
 - Verification scripts now support API key headers and optional agent build flags.
 - Optional HTTP listener when mTLS is enabled to keep dashboard/AI traffic on port 8080.
 - v2.3 release notes (`docs/Release-Notes-v2.3.md`) and PR acceptance template (`docs/PR-Template-v2.3-Acceptance.md`).
+- Course-process docs pack: issue templates (bug/feature/task), expanded PR template, and v2.3 Mermaid class diagrams.
 
 ### Changed
 - Agent now injects W3C trace headers for HTTP requests.
diff --git a/README.md b/README.md
index ace45f1..b6f3032 100644
--- a/README.md
+++ b/README.md
@@ -194,6 +194,7 @@ Open the dashboard at http://localhost:3000.
 - Observability (OpenTelemetry): docs/Observability.md
 - v2.3 architecture roadmap: docs/ARCHITECTURE-v2.3.md
 - v2.3 delivery roadmap: docs/ROADMAP-v2.3.md
+- v2.3 class diagrams (Mermaid): docs/diagrams/Class-Diagram-v2.3.md
 - v2.3 Milestone 1 smoke test: docs/QA-SmokeTest-v2.3-M1.md
 - v2.3 M2 data provenance: docs/Data-Provenance-v2.3-M2.md
 - v2.3 M2 data acquisition scripts: scripts/data_acquisition/README.md
diff --git a/docs/diagrams/Class-Diagram-v2.3.md b/docs/diagrams/Class-Diagram-v2.3.md
new file mode 100644
index 0000000..7c16bff
--- /dev/null
+++ b/docs/diagrams/Class-Diagram-v2.3.md
@@ -0,0 +1,222 @@
+# v2.3 Class Diagrams (Mermaid)
+
+This document provides UML-style class diagrams for the four major service domains:
+
+- Core (.NET)
+- Agent (C++)
+- AI Engine (Python/FastAPI)
+- Web Dashboard (Next.js)
+
+## Cross-Service Overview
+
+```mermaid
+classDiagram
+  class AgentService {
+    +register()
+    +heartbeat()
+    +checkpoint()
+    +restore()
+  }
+
+  class CoreApi {
+    +ingestTelemetry()
+    +queueCommand()
+    +runMigrationCycle()
+    +getDashboardLatest()
+  }
+
+  class AiEngine {
+    +analyze()
+    +enrichSignals()
+    +enrichSignalsBatch()
+  }
+
+  class WebDashboard {
+    +fetchFleetStatus()
+    +fetchRiskHistory()
+    +renderExplainability()
+  }
+
+  class PostgreSQL
+  class RabbitMQ
+  class SnapshotStorage
+
+  AgentService --> CoreApi : telemetry/heartbeat
+  CoreApi --> AiEngine : risk + enrichment calls
+  CoreApi --> PostgreSQL : persistence
+  CoreApi --> RabbitMQ : async ingestion
+  CoreApi --> SnapshotStorage : snapshot artifacts
+  WebDashboard --> CoreApi : dashboard APIs
+```
+
+## Core (.NET)
+
+```mermaid
+classDiagram
+  class DashboardController {
+    +GetLatest()
+    +GetHistory()
+  }
+
+  class ControlPlaneService {
+    +QueueCommandAsync()
+    +GetLatestAsync()
+    +GetHistoryAsync()
+  }
+
+  class TelemetryIngestionService {
+    +IngestAsync()
+  }
+
+  class MigrationOrchestrator {
+    +RunMigrationCycle()
+  }
+
+  class DynamicRiskPolicy {
+    +Evaluate()
+    +ComputeAlpha()
+  }
+
+  class AnalysisService {
+    +AnalyzeAsync()
+  }
+
+  class CommandService {
+    +QueueCommand()
+  }
+
+  class TelemetryStore {
+    +Update()
+    +GetLatest()
+  }
+
+  class ApplicationDbContext
+  class TelemetryPayload
+  class AnalysisResult
+
+  DashboardController --> ControlPlaneService
+  ControlPlaneService --> TelemetryStore
+  ControlPlaneService --> CommandService
+  ControlPlaneService --> DynamicRiskPolicy
+  ControlPlaneService --> ApplicationDbContext
+  TelemetryIngestionService --> AnalysisService
+  TelemetryIngestionService --> TelemetryStore
+  MigrationOrchestrator --> DynamicRiskPolicy
+  MigrationOrchestrator --> AnalysisService
+  MigrationOrchestrator --> CommandService
+  TelemetryStore --> TelemetryPayload
+  TelemetryStore --> AnalysisResult
+```
+
+## Agent (C++)
+
+```mermaid
+classDiagram
+  class NetworkClient {
+    +Register()
+    +Heartbeat()
+    +PollCommands()
+    +SendFeedback()
+  }
+
+  class CommandPoller {
+    +Poll()
+  }
+
+  class CommandDispatcher {
+    +Dispatch()
+  }
+
+  class InferenceEngine {
+    +Initialize()
+    +Evaluate()
+  }
+
+  class ArchiveManager {
+    +CreateSnapshotArchive()
+    +RestoreFromSnapshot()
+  }
+
+  class CriuManager {
+    +Checkpoint()
+    +Restore()
+  }
+
+  class LifecycleManager {
+    +Start()
+    +Stop()
+  }
+
+  class SemanticFeatures
+
+  LifecycleManager --> NetworkClient
+  LifecycleManager --> CommandPoller
+  CommandPoller --> CommandDispatcher
+  CommandDispatcher --> ArchiveManager
+  CommandDispatcher --> InferenceEngine
+  ArchiveManager --> CriuManager
+  InferenceEngine --> SemanticFeatures
+```
+
+## AI Engine (Python / FastAPI)
+
+```mermaid
+classDiagram
+  class FastAPIApp {
+    +POST /analyze
+    +POST /signals/enrich
+    +POST /signals/enrich/batch
+  }
+
+  class RiskModel {
+    +analyzeTelemetry()
+  }
+
+  class SignalEnrichmentModel {
+    +enrichSignal()
+    +enrichBatch()
+  }
+
+  class FinBertAdapter {
+    +predictSentiment()
+  }
+
+  class Summarizer {
+    +summarize()
+  }
+
+  FastAPIApp --> RiskModel
+  FastAPIApp --> SignalEnrichmentModel
+  SignalEnrichmentModel --> FinBertAdapter
+  SignalEnrichmentModel --> Summarizer
+```
+
+## Web Dashboard (Next.js)
+
+```mermaid
+classDiagram
+  class DashboardClient {
+    +load()
+    +handleSimulateChaos()
+  }
+
+  class ApiLib {
+    +fetchFleetStatus()
+    +fetchRiskHistory()
+    +fetchAuditLogs()
+  }
+
+  class ExplainabilityPanel {
+    +render(alpha, P_preempt, topSignals)
+  }
+
+  class ExternalSignalsPanel
+  class ControlPanel
+  class HistoryChart
+
+  DashboardClient --> ApiLib
+  DashboardClient --> ExplainabilityPanel
+  DashboardClient --> ExternalSignalsPanel
+  DashboardClient --> ControlPanel
+  DashboardClient --> HistoryChart
+```