Jdbc workers

[v1r3n]

Pull Request type

• Bugfix
• Feature
• Refactoring (no functional changes, no api changes)
• Build related changes
• WHOSUSING.md
• Other (please describe):

NOTE: Please remember to run ./gradlew spotlessApply to fix any format violations.

1. JDBC Worker Task (Feature)

New system task that enables workflows to execute SQL queries against configured database instances. Includes:

• JDBCWorker — executes SELECT/INSERT/UPDATE/DELETE with parameterized queries and connection pooling
• JDBCProvider / JDBCInstanceConfig / JDBCConnectionConfig — type-safe, named instance configuration under conductor.jdbc.instances
• Full test coverage: unit tests for config, provider, and worker + end-to-end test with in-memory H2
• Documentation added at docs/documentation/configuration/workflowdef/systemtasks/jdbc-task.md

2. SQLite search-v2 fix (Bugfix)

SqliteIndexDAO.searchWorkflows() and searchTasks() returned full JSON blobs instead of IDs, breaking the v2 search API contract. Fixed SqliteIndexQueryBuilder to accept a selectColumn parameter so v2 search
selects workflow_id/task_id only. Added 6 test cases covering basic search, pagination with ordering, and null sort handling.

3. Documentation site fixes (Bugfix)

• Reverted use_directory_urls to false to preserve backward-compatible .html URLs from v3.22.1
• Fixed 21 broken internal links across 10 files (HTML tags, wrong relative paths, non-existent anchor fragments)
• Relocated SDK docs from devguide/sdk/ to documentation/clientsdks/ to match nav structure
• Added custom 404 page
• 99 pages crawled, 20,506 internal links verified, 0 broken

Alternatives considered

JDBC Task: Considered implementing as a pure worker (external process) rather than a system task. A system task was chosen because it runs on the server with managed connection pools — avoiding the need for
every worker deployment to carry database credentials and connection config.

SQLite search-v2: Considered adding a separate query method to SqliteIndexDAO instead of modifying the query builder. Chose to extend SqliteIndexQueryBuilder.getQuery() with a selectColumn overload to keep
the fix minimal and co-located with the existing query construction logic.

Docs URL format: Considered keeping use_directory_urls: true (directory-style URLs like /java-sdk/). Reverted to false to avoid breaking all existing external links pointing to .html URLs from the v3.22.1
site.