feat(java): embed Rust CLI runtime as native module

Squashed from PR #2295 (branch edburns/…-review-02).
Includes Java multi-module Maven restructure, copilot-native
submodule for bundling the Rust CLI runtime, codegen updates,
and related workflow changes.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 90cbda40-cda3-4ecd-b381-9f9ba0573d0a

Author: edburns

.github/workflows/codegen-check.yml

@@ -15,7 +15,7 @@ on:
       - 'go/rpc/**'
       - 'rust/src/generated/**'
       - 'sdk-protocol-version.json'
-      - 'java/src/main/java/com/github/copilot/SdkProtocolVersion.java'
+      - 'java/sdk/src/main/java/com/github/copilot/SdkProtocolVersion.java'
       - '.github/workflows/codegen-check.yml'
   workflow_dispatch:
 
@@ -84,7 +84,7 @@ jobs:
       - name: Verify Java protocol version matches
         run: |
           EXPECTED=$(jq -r '.version' sdk-protocol-version.json)
-          ACTUAL=$(grep -oP 'LATEST\(\K[0-9]+' java/src/main/java/com/github/copilot/SdkProtocolVersion.java)
+          ACTUAL=$(grep -oP 'LATEST\(\K[0-9]+' java/sdk/src/main/java/com/github/copilot/SdkProtocolVersion.java)
           if [ "$EXPECTED" != "$ACTUAL" ]; then
             echo "::error::Java SDK protocol version ($ACTUAL) does not match sdk-protocol-version.json ($EXPECTED). Java manages its own SdkProtocolVersion.java via java/scripts/codegen/. Update it to match."
             exit 1

.github/workflows/docs-validation.yml

@@ -9,8 +9,9 @@ on:
       - 'python/copilot/**'
       - 'go/**/*.go'
       - 'dotnet/src/**'
-      - 'java/src/**'
+      - 'java/sdk/src/**'
       - 'java/pom.xml'
+      - 'java/sdk/pom.xml'
       - 'scripts/docs-validation/**'
       - '.github/workflows/docs-validation.yml'
   workflow_dispatch:

.github/workflows/java-adapt-handwritten-code-to-accept-upgrade-changes.lock.yml

@@ -51,17 +51,17 @@ You are an automation agent that fixes handwritten Java SDK source and test code
 
 - The branch `${{ inputs.branch }}` already has:
   - Updated `java/scripts/codegen/package.json` with the new version
-  - Regenerated `java/src/generated/java/` code that compiles successfully
+  - Regenerated `java/sdk/src/generated/java/` code that compiles successfully
   - Updated the Java POM CLI/version pin property
 - Your job is ONLY to fix **handwritten** code, NOT generated code.
 
 ## Boundaries
 
-- ❌ Do NOT edit anything under `java/src/generated/java/`
+- ❌ Do NOT edit anything under `java/sdk/src/generated/java/`
 - ❌ Do NOT edit `java/scripts/codegen/java.ts`
-- ❌ Do NOT create or modify tests in the `com.github.copilot.generated` test package (`java/src/test/java/com/github/copilot/sdk/generated/`)
-- ✅ DO edit `java/src/main/java/com/github/copilot/sdk/**`
-- ✅ DO edit `java/src/test/java/com/github/copilot/sdk/**` (excluding the `generated` subpackage)
+- ❌ Do NOT create or modify tests in the `com.github.copilot.generated` test package (`java/sdk/src/test/java/com/github/copilot/sdk/generated/`)
+- ✅ DO edit `java/sdk/src/main/java/com/github/copilot/sdk/**`
+- ✅ DO edit `java/sdk/src/test/java/com/github/copilot/sdk/**` (excluding the `generated` subpackage)
 - ✅ DO add new test methods or test classes if new user-facing API surface is introduced
 
 ## Instructions
@@ -146,7 +146,7 @@ mvn verify -Dskip.test.harness=true
 If this passes, commit and push:
 
 ```bash
-git add java/src/main/java java/src/test/java
+git add java/sdk/src/main/java java/sdk/src/test/java
 git commit -m "Fix handwritten Java code for @github/copilot schema changes
 
 Adapt constructor calls, enum references, and test assertions to match

.github/workflows/java-adapt-handwritten-code-to-accept-upgrade-changes.md

@@ -6,12 +6,12 @@ on:
       - main
     paths:
       - 'java/scripts/codegen/**'
-      - 'java/src/generated/**'
+      - 'java/sdk/src/generated/**'
       - '.github/workflows/java-codegen-check.yml'
   pull_request:
     paths:
       - 'java/scripts/codegen/**'
-      - 'java/src/generated/**'
+      - 'java/sdk/src/generated/**'
       - '.github/workflows/java-codegen-check.yml'
   workflow_dispatch:
 

.github/workflows/java-codegen-check.yml

@@ -54,7 +54,7 @@ You are an automation agent that fixes Java compilation and test failures caused
 
 A Dependabot PR bumped the `@github/copilot` npm dependency in `java/scripts/codegen/package.json`. The `java-codegen-check` workflow ran the code generator (`java/scripts/codegen/java.ts`) against the new schemas and `mvn verify` subsequently failed. Your job is to fix **both** the code generator script (if needed) and the handwritten SDK/test source code so the build passes.
 
-**❌❌❌ YOU MUST NEVER EDIT any of the java source code in `java/src/generated/` directly.** ✅✅Rather, the way to affect changes in these files is to change the code generator script and re-generate the classes in `java/src/generated`.
+**❌❌❌ YOU MUST NEVER EDIT any of the java source code in `java/sdk/src/generated/` directly.** ✅✅Rather, the way to affect changes in these files is to change the code generator script and re-generate the classes in `java/sdk/src/generated`.
 
 The branch to fix is: `${{ inputs.branch }}`
 The PR number is: `${{ inputs.pr_number }}`
@@ -66,7 +66,7 @@ ${{ inputs.error_summary }}
 
 ## Architecture overview
 
-The code generator (`java/scripts/codegen/java.ts`) reads JSON schemas from `node_modules/@github/copilot/schemas/` and produces Java source files under `java/src/generated/java/`. These generated types are consumed by handwritten code in `java/src/main/java/` (primarily `CopilotSession.java`) and tested by handwritten tests in `java/src/test/java/`.
+The code generator (`java/scripts/codegen/java.ts`) reads JSON schemas from `node_modules/@github/copilot/schemas/` and produces Java source files under `java/sdk/src/generated/java/`. These generated types are consumed by handwritten code in `java/sdk/src/main/java/` (primarily `CopilotSession.java`) and tested by handwritten tests in `java/sdk/src/test/java/`.
 
 When `@github/copilot` is bumped, the schemas may change in ways the code generator does not yet handle. Common schema changes include:
 
@@ -126,7 +126,7 @@ Before making fixes, determine whether the failure is caused by:
 - New schemas exist but no corresponding Java types were generated
 
 **(B) Handwritten code referencing old generated type names/shapes.** Signs:
-- Compilation errors in `java/src/main/java/` or `java/src/test/java/` referencing types that no longer exist
+- Compilation errors in `java/sdk/src/main/java/` or `java/sdk/src/test/java/` referencing types that no longer exist
 - Test data using old JSON field names
 
 Often **both** (A) and (B) apply: the codegen needs fixing first, then handwritten code needs updating.
@@ -162,7 +162,7 @@ If the diagnosis shows the code generator does not handle the new schema format:
 
 4. **Verify the generated output** looks reasonable:
    ```bash
-   git diff --stat java/src/generated/java/
+   git diff --stat java/sdk/src/generated/java/
    ```
 
 **You may ONLY modify `java/scripts/codegen/java.ts`.** Do not modify `package.json`, `package-lock.json`, or any other file under `java/scripts/codegen/`.
@@ -179,12 +179,12 @@ For each attempt:
 2. **Read the generated types** to understand what changed. Check the generated files that the handwritten code references:
    ```bash
    # Example: check what a generated type looks like now
-   cat java/src/generated/java/com/github/copilot/generated/rpc/<TypeName>.java
+   cat java/sdk/src/generated/java/com/github/copilot/generated/rpc/<TypeName>.java
    ```
 
 3. **Fix the affected source files.** You may modify files under:
-   - `java/src/main/java/` — handwritten SDK source code
-   - `java/src/test/java/` — handwritten test code
+   - `java/sdk/src/main/java/` — handwritten SDK source code
+   - `java/sdk/src/test/java/` — handwritten test code
 
    Common fixes:
    - Update type references from old nested types to new standalone types (e.g. `SessionMcpListResultServersItem` → `McpServer`)
@@ -236,12 +236,12 @@ Do **NOT** push broken code.
 
 ## Important constraints
 
-- **NEVER** hand-edit files under `java/src/generated/java/` — these are auto-generated. They are updated by running `cd java/scripts/codegen && npx tsx java.ts`.
-- **NEVER** modify `java/pom.xml` — build config is not in scope
+- **NEVER** hand-edit files under `java/sdk/src/generated/java/` — these are auto-generated. They are updated by running `cd java/scripts/codegen && npx tsx java.ts`.
+- **NEVER** modify `java/sdk/pom.xml` — build config is not in scope
 - **NEVER** modify `java/scripts/codegen/package.json` or `java/scripts/codegen/package-lock.json` — dependency versions are not in scope
 - **NEVER** modify files under `.github/` — workflow files are not in scope
 - You **MAY** modify `java/scripts/codegen/java.ts` to fix the code generator
-- You **MAY** modify files under `java/src/main/java/` and `java/src/test/java/` to fix handwritten code
+- You **MAY** modify files under `java/sdk/src/main/java/` and `java/sdk/src/test/java/` to fix handwritten code
 - Always run `cd java && mvn spotless:apply` before committing to ensure code formatting
 - Maximum 3 fix attempts before reporting failure via `noop`
 - Only push if `mvn verify` passes

.github/workflows/java-codegen-fix.lock.yml

@@ -17,6 +17,52 @@ permissions:
   contents: read
 
 jobs:
+  java-sdk-inprocess:
+    name: "Java SDK InProcess Tests"
+    if: github.event.repository.fork == false
+    runs-on: ubuntu-latest
+    continue-on-error: true
+    defaults:
+      run:
+        shell: bash
+        working-directory: ./java
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
+
+      - uses: actions/setup-java@be666c2fcd27ec809703dec50e508c2fdc7f6654 # v5
+        with:
+          java-version: "25"
+          distribution: "microsoft"
+          cache: "maven"
+
+      - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+        with:
+          node-version: 22
+
+      - name: Run Java SDK tests (InProcess)
+        env:
+          CI: "true"
+        run: mvn clean verify -Pinprocess
+
+      - name: Generate Test Report Summary
+        if: always()
+        uses: ./.github/actions/java-test-report
+        with:
+          title: "Copilot Java SDK :: Test Results InProcess"
+
+      - name: Upload test results on failure
+        if: failure()
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
+        with:
+          name: java-test-results-inprocess
+          path: |
+            java/sdk/target/surefire-reports/
+            java/sdk/target/surefire-reports-isolated/
+            java/sdk/target/failsafe-reports/
+          retention-days: 7
+
   java-sdk:
     name: "Java SDK Tests (JDK ${{ matrix.test-jdk }})"
     if: github.event.repository.fork == false
@@ -96,17 +142,17 @@ jobs:
         run: |
           echo "Running tests against JDK 25-built classes using JDK 17 runtime..."
           java -version
-          mvn jacoco:prepare-agent@wire-up-coverage-instrumentation antrun:run@print-test-jdk-banner surefire:test failsafe:integration-test failsafe:verify jacoco:report@build-coverage-report-from-tests -Denforcer.skip=true
+          mvn -pl sdk jacoco:prepare-agent@wire-up-coverage-instrumentation antrun:run@print-test-jdk-banner surefire:test failsafe:integration-test failsafe:verify jacoco:report@build-coverage-report-from-tests -Denforcer.skip=true
 
       - name: Upload test results for site generation
         if: success() && github.ref == 'refs/heads/main' && matrix.test-jdk == '25'
         uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: test-results-for-site
           path: |
-            java/target/jacoco-test-results/sdk-tests.exec
-            java/target/surefire-reports/
-            java/target/surefire-reports-isolated/
+            java/sdk/target/jacoco-test-results/sdk-tests.exec
+            java/sdk/target/surefire-reports/
+            java/sdk/target/surefire-reports-isolated/
           retention-days: 1
 
       - name: Generate Test Report Summary
@@ -121,7 +167,7 @@ jobs:
         with:
           name: java-test-results-jdk-${{ matrix.test-jdk }}
           path: |
-            java/target/surefire-reports/
-            java/target/surefire-reports-isolated/
-            java/target/failsafe-reports/
+            java/sdk/target/surefire-reports/
+            java/sdk/target/surefire-reports-isolated/
+            java/sdk/target/failsafe-reports/
           retention-days: 7