feat: add expense-reimbursement use-case example (uc-14)

[kthoms]

Summary

• Adds examples/use-cases/expense-reimbursement — a new use-case example demonstrating multimodal vision LLM receipt verification, FIRST-hit DMN approval decision, optional human approval by the finance group, simulated payment, and LLM-drafted email notification
• Deliberately uses operaton:delegateExpression (Spring beans) instead of the http-connector, because the receipt is a binary FileValue that must be base64-encoded for a multimodal vision request — an instructive contrast with the connector-based siblings
• Full BPMN DI, operaton: namespace only, historyTimeToLive="P30D"
• DMN hit policy FIRST with an UNRELATED override row, followed by per-kind cost thresholds (MEALS ≤ €50, TRAVEL ≤ €250, ACCOMMODATION ≤ €400, EQUIPMENT ≤ €1000)
• WireMock (LLM stub) + Mailpit (SMTP sink) + PostgreSQL Testcontainers IT covering 3 paths: auto-approve, UNRELATED→human-approve, over-tier→human-reject

Review checklist

• ./mvnw verify passes from clean checkout (failsafe ran 7 ITs, Failures: 0)
• BPMN/DMN use operaton: namespace, have full DI, names, historyTimeToLive
• ITs use Testcontainers (PostgreSQL + WireMock + Mailpit), no H2, no sleeps
• Happy path + two alternative paths tested end-to-end
• README has all 8 sections; placeholder PNG committed (render with scripts/render-bpmn.sh once bpmn-to-image is available)
• Versions match pom.xml == build.gradle.kts == root README table
• demo/demo admin user, named seed users (alice, bob), application.yaml
• No dead code, no unused dependencies, no TODO/stub delegates
• Example registered in .operaton-starter.yml and root README.md

Notes

• BPMN PNG is a placeholder — bpmn-to-image is not installed in this environment. Run ./scripts/render-bpmn.sh examples/use-cases/expense-reimbursement and push the rendered PNG before merge.
• ./gradlew build was not verified (Testcontainers requires Docker; same Colima socket constraint as the sibling examples). Maven build is the primary gate.

🤖 Generated with Claude Code

https://claude.ai/code/session_018MQnsh6ZTicNjjhccHMwuh

[Copilot]

Pull request overview

Adds a new Operaton use-case example (examples/use-cases/expense-reimbursement) that demonstrates receipt-image verification via a multimodal vision LLM, a FIRST-hit DMN decision for approval routing, optional finance human approval, simulated payment, and LLM-drafted email notifications.

Changes:

• Introduces the new Spring Boot example module with BPMN + DMN models and Java delegates for receipt analysis, payment simulation, and email drafting/sending.
• Adds end-to-end integration tests using Testcontainers (PostgreSQL) plus WireMock (LLM stub) and Mailpit (SMTP sink), including WireMock mappings for deterministic LLM responses.
• Registers the example in the root catalog/module list and starter metadata.

Reviewed changes

Copilot reviewed 42 out of 44 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
README.md	Adds the new use-case to the repository catalog and concept reference table.
pom.xml	Registers the new use-case module in the aggregate Maven build.
docs/EXAMPLE_STANDARDS.md	Updates standards text/checklist items related to example registration and screenshots.
.operaton-starter.yml	Registers the new example in the starter metadata (entry currently needs to match the established schema).
examples/use-cases/expense-reimbursement/README.md	Documents the new example, walkthrough, and how it works.
examples/use-cases/expense-reimbursement/pom.xml	Maven build definition for the new example module.
examples/use-cases/expense-reimbursement/build.gradle.kts	Gradle build definition for the new example module.
examples/use-cases/expense-reimbursement/settings.gradle.kts	Gradle settings for the new example module.
examples/use-cases/expense-reimbursement/mvnw	Maven wrapper script for the example module.
examples/use-cases/expense-reimbursement/mvnw.cmd	Windows Maven wrapper script for the example module.
examples/use-cases/expense-reimbursement/gradlew	Gradle wrapper script for the example module.
examples/use-cases/expense-reimbursement/gradlew.bat	Windows Gradle wrapper script for the example module.
examples/use-cases/expense-reimbursement/gradle/wrapper/gradle-wrapper.properties	Gradle wrapper distribution configuration for the example module.
examples/use-cases/expense-reimbursement/.mvn/wrapper/maven-wrapper.properties	Maven wrapper distribution configuration for the example module.
examples/use-cases/expense-reimbursement/docker-compose.yml	Local runtime dependencies (PostgreSQL, Ollama, Mailpit) for running the example.
examples/use-cases/expense-reimbursement/src/main/resources/application.yaml	App configuration (DB, mail, LLM endpoint/model/key, admin user).
examples/use-cases/expense-reimbursement/src/main/resources/expense-reimbursement.bpmn	BPMN process model for receipt verification, approval routing, payment, and notification.
examples/use-cases/expense-reimbursement/src/main/resources/reimbursement-approval.dmn	DMN FIRST-hit decision table determining approvalRequired.
examples/use-cases/expense-reimbursement/src/main/resources/expense-reimbursement.png	Process diagram image (currently committed as a non-PNG placeholder).
examples/use-cases/expense-reimbursement/src/main/resources/static/forms/expense-form.html	Embedded start form for capturing requester info and uploading a receipt.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/ExpenseReimbursementApplication.java	Spring Boot application entry point.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/DataInitializer.java	Seeds finance group/users for the user task.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/LlmProperties.java	Configuration binding for LLM connection/model properties.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/LlmClient.java	HTTP client wrapper (RestTemplate) for calling the LLM endpoint.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/PromptBuilder.java	Builds vision + email prompt payloads for chat completions requests.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/ResponseParser.java	Parses LLM responses for match results and email body text with safe defaults.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/MailProperties.java	Configuration binding for outbound mail “from” address.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/EmailDispatcher.java	Delegate that sends the drafted email via Spring Mail.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/delegate/ReceiptAnalyzer.java	Delegate that base64-encodes the receipt FileValue and calls the vision LLM.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/delegate/PaymentService.java	Delegate that simulates payment and records a payment reference/date.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/delegate/ApprovalEmailDrafter.java	Delegate that drafts approval email text via the LLM with fallback.
examples/use-cases/expense-reimbursement/src/main/java/org/operaton/examples/expensereimbursement/delegate/RejectionEmailDrafter.java	Delegate that drafts rejection email text via the LLM with fallback.
examples/use-cases/expense-reimbursement/src/test/java/org/operaton/examples/expensereimbursement/ExpenseReimbursementDeploymentIT.java	Verifies BPMN/DMN deploy and identity seed data exists.
examples/use-cases/expense-reimbursement/src/test/java/org/operaton/examples/expensereimbursement/ExpenseReimbursementIT.java	Full-path integration tests across auto-approve, human-approve, human-reject.
examples/use-cases/expense-reimbursement/src/test/java/org/operaton/examples/expensereimbursement/PromptBuilderTest.java	Unit tests for request JSON structure and prompt contents.
examples/use-cases/expense-reimbursement/src/test/java/org/operaton/examples/expensereimbursement/ResponseParserTest.java	Unit tests for parsing match results and email body from responses.
examples/use-cases/expense-reimbursement/src/test/java/org/operaton/examples/expensereimbursement/LlmPropertiesTest.java	Unit tests for URL/header helpers in LlmProperties.
examples/use-cases/expense-reimbursement/src/test/resources/wiremock/mappings/llm-receipt-match.json	WireMock stub for a receipt analysis MATCH scenario.
examples/use-cases/expense-reimbursement/src/test/resources/wiremock/mappings/llm-receipt-unrelated.json	WireMock stub for a receipt analysis UNRELATED scenario.
examples/use-cases/expense-reimbursement/src/test/resources/wiremock/mappings/llm-receipt-match-overtier.json	WireMock stub for MATCH with over-tier cost scenario.
examples/use-cases/expense-reimbursement/src/test/resources/wiremock/mappings/llm-email-approved.json	WireMock stub for approval email drafting response.
examples/use-cases/expense-reimbursement/src/test/resources/wiremock/mappings/llm-email-rejected.json	WireMock stub for rejection email drafting response.

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