chore(ci): rationalize CI into single workflow with unified comment

Consolidate CI test infrastructure into a single incremental-build
action with a unified PR comment, replacing the previous scattered
approach with separate component-test and detect-dependencies actions.

Key changes:

- Merge component-test and detect-dependencies actions into
  incremental-build, which now handles file-path analysis, POM
  dependency detection, and /component-test extra modules in one script

- Add POM dependency analysis: when parent/pom.xml properties change,
  grep all module pom.xml files for references to the changed properties
  and include those modules in the test set

- Add pr-test-commenter.yml workflow: posts CI test summary comments
  using workflow_run trigger so it works on fork PRs (where GITHUB_TOKEN
  is read-only)

- Refactor pr-manual-component-test.yml: instead of running its own
  build, it now resolves component paths and dispatches the main
  "Build and test" workflow with extra_modules and skip_full_build

- Add manual-it-mapping.txt: maps source modules to their associated
  integration test suites. When a changed module is in the exclusion
  list but has a mapping entry, CI advises contributors to run the
  integration tests manually

- Add CI-ARCHITECTURE.md documenting the full CI workflow ecosystem

- Fix empty associative array crash under set -u in checkManualItTests
  by using a counter variable instead of ${#it_sources[@]}

- Fix duplicate modules in CI comment by stripping Maven [packaging]
  suffix before deduplication

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: gnodet

.github/CI-ARCHITECTURE.md

@@ -0,0 +1,164 @@
+# CI Architecture
+
+Overview of the GitHub Actions CI/CD ecosystem for Apache Camel.
+
+## Workflow Overview
+
+```
+PR opened/updated
+       │
+       ├──► pr-id.yml ──► pr-commenter.yml (welcome message)
+       │
+       ├──► pr-build-main.yml (Build and test)
+       │        │
+       │        ├── regen.sh (full build, no tests)
+       │        ├── incremental-build (test affected modules)
+       │        │       ├── File-path analysis
+       │        │       ├── POM dependency analysis
+       │        │       └── Extra modules (/component-test)
+       │        │
+       │        └──► pr-test-commenter.yml (post unified comment)
+       │
+       └──► sonar-build.yml ──► sonar-scan.yml (SonarCloud analysis)
+                                    [currently disabled — INFRA-27808]
+
+PR comment: /component-test kafka http
+       │
+       └──► pr-manual-component-test.yml
+                │
+                └── dispatches "Build and test" with extra_modules
+```
+
+## Workflows
+
+### `pr-build-main.yml` — Build and test
+
+- **Trigger**: `pull_request` (main branch), `workflow_dispatch`
+- **Matrix**: JDK 17, 21, 25 (25 is experimental)
+- **Steps**:
+  1. Full build via `regen.sh` (`mvn install -DskipTests -Pregen`)
+  2. Check for uncommitted generated files
+  3. Run incremental tests (only affected modules)
+  4. Upload test comment as artifact
+- **Inputs** (workflow_dispatch): `pr_number`, `pr_ref`, `extra_modules`, `skip_full_build`
+
+### `pr-test-commenter.yml` — Post CI test comment
+
+- **Trigger**: `workflow_run` on "Build and test" completion
+- **Purpose**: Posts the unified test summary comment on the PR
+- **Why separate**: Uses `workflow_run` to run in base repo context, allowing comment posting on fork PRs (where `GITHUB_TOKEN` is read-only)
+
+### `pr-manual-component-test.yml` — /component-test handler
+
+- **Trigger**: `issue_comment` with `/component-test` prefix
+- **Who**: MEMBER, OWNER, or CONTRIBUTOR only
+- **What**: Resolves component names to module paths, dispatches the main "Build and test" workflow with `extra_modules` and `skip_full_build=true`
+- **Build**: Uses a quick targeted build (`-Dquickly`) of the requested modules and their dependencies instead of the full `regen.sh` build
+
+### `pr-id.yml` + `pr-commenter.yml` — Welcome message
+
+- **Trigger**: `pull_request` (all branches)
+- **Purpose**: Posts the one-time welcome message on new PRs
+- **Why two workflows**: `pr-id.yml` runs in PR context (uploads PR number), `pr-commenter.yml` runs via `workflow_run` with write permissions
+
+### `main-build.yml` — Main branch build
+
+- **Trigger**: `push` to main, camel-4.14.x, camel-4.18.x
+- **Steps**: Same as PR build but without comment posting
+
+### `sonar-build.yml` + `sonar-scan.yml` — SonarCloud PR analysis
+
+- **Status**: Temporarily disabled (INFRA-27808 — SonarCloud quality gate adjustment pending)
+- **Trigger**: `pull_request` (main branch) → `workflow_run` on SonarBuild completion
+- **Why two workflows**: `sonar-build.yml` runs in PR context (builds with JaCoCo coverage on core modules, uploads compiled classes artifact), `sonar-scan.yml` runs via `workflow_run` with secrets access to run the Sonar scanner and post results
+- **Coverage scope**: Currently limited to core modules (`camel-api`, `camel-core`, etc.) and `coverage` aggregator. Component coverage planned for future integration with `incremental-build.sh` module detection
+
+### Other workflows
+
+- `pr-labeler.yml` — Auto-labels PRs based on changed files
+- `pr-doc-validation.yml` — Validates documentation changes
+- `pr-cleanup-branches.yml` — Cleans up merged PR branches
+- `alternative-os-build-main.yml` — Tests on non-Linux OSes
+- `check-container-versions.yml` — Checks test container version updates
+- `generate-sbom-main.yml` — Generates SBOM for releases
+- `security-scan.yml` — Security vulnerability scanning
+
+## Actions
+
+### `incremental-build`
+
+The core test runner. Determines which modules to test using:
+
+1. **File-path analysis**: Maps changed files to Maven modules
+2. **POM dependency analysis**: For `parent/pom.xml` changes, detects property changes and finds modules that reference the affected properties in their `pom.xml` files (uses simple grep, not Maveniverse Toolbox — see Known Limitations below)
+3. **Extra modules**: Additional modules passed via `/component-test`
+
+Results are merged, deduplicated, and tested. The script also:
+
+- Detects tests disabled in CI (`@DisabledIfSystemProperty(named = "ci.env.name")`)
+- Applies an exclusion list for generated/meta modules
+- Checks for excluded modules with associated integration tests (via `manual-it-mapping.txt`) and advises contributors to run them manually
+- Generates a unified PR comment with all test information
+
+### `install-mvnd`
+
+Installs the Maven Daemon (mvnd) for faster builds.
+
+### `install-packages`
+
+Installs system packages required for the build.
+
+## PR Labels
+
+| Label | Effect |
+| --- | --- |
+| `skip-tests` | Skip all tests |
+| `test-dependents` | Force testing dependent modules even if threshold exceeded |
+
+## CI Environment
+
+The CI sets `-Dci.env.name=github.com` via `MVND_OPTS` (in `install-mvnd`). Tests can use `@DisabledIfSystemProperty(named = "ci.env.name")` to skip flaky tests in CI. The test comment warns about these skipped tests.
+
+## Known Limitations of POM Dependency Detection
+
+The property-grep approach has structural limitations that can cause missed modules:
+
+1. **Managed dependencies without explicit** `<version>` — Most Camel modules inherit dependency versions via `<dependencyManagement>` in the parent POM and do not declare `<version>${property}</version>` themselves. When a managed dependency version property changes, only modules that explicitly reference the property are detected — modules relying on inheritance are missed.
+
+2. **Maven plugin version changes are completely invisible** — Plugin version properties (e.g. `<maven-surefire-plugin-version>`) are both defined and consumed in `parent/pom.xml` via `<pluginManagement>`. Since the module search excludes `parent/pom.xml`, no modules are found and **no tests run at all** for plugin updates. Modules inherit plugins from the parent without any `${property}` reference in their own `pom.xml`.
+
+3. **BOM imports** — When a BOM version property changes (e.g. `<spring-boot-bom-version>`), modules using artifacts from that BOM are not detected because they reference the BOM's artifacts, not the BOM property.
+
+4. **Transitive dependency changes** — Modules affected only via transitive dependencies are not detected.
+
+5. **Non-property version changes** — Direct edits to `<version>` values (not using `${property}` substitution) or structural changes to `<dependencyManagement>` sections are not caught.
+
+These limitations mean the incremental build may under-test when parent POM properties change. A future improvement could use [Maveniverse Toolbox](https://github.com/maveniverse/toolbox) `tree-find` or [Scalpel](https://github.com/maveniverse/scalpel) to resolve the full dependency graph and detect all affected modules.
+
+## Manual Integration Test Advisories
+
+Some modules are excluded from CI's `-amd` expansion (the `EXCLUSION_LIST`) because they are generated code, meta-modules, or expensive integration test suites. When a contributor changes one of these modules, CI cannot automatically test all downstream effects.
+
+The file `manual-it-mapping.txt` (co-located with the incremental build script) maps source modules to their associated integration test suites. When a changed module has a mapping entry, CI posts an advisory in the PR comment:
+
+> You modified `dsl/camel-jbang/camel-jbang-core`. The related integration tests in `dsl/camel-jbang/camel-jbang-it` are excluded from CI. Consider running them manually:
+>
+> ```
+> mvn verify -f dsl/camel-jbang/camel-jbang-it -Djbang-it-test
+> ```
+
+To add new mappings, edit `manual-it-mapping.txt` using the format:
+
+```
+source-artifact-id:it-module-path:command
+```
+
+## Multi-JDK Artifact Behavior
+
+All non-experimental JDK matrix entries (17, 21) upload the CI comment artifact with `overwrite: true`. This ensures a comment is posted even if one JDK build fails. Since the comment content is identical across JDKs (same modules are tested regardless of JDK version), last writer wins.
+
+## Comment Markers
+
+PR comments use HTML markers for upsert (create-or-update) behavior:
+
+- `<!-- ci-tested-modules -->` — Unified test summary comment