feat: add SQLite backend support and migrations

[niteshpurohit]

• Introduced a new SQLite backend for Karya, allowing users to configure and use SQLite as a job queue store.
• Added tests for the SQLite backend to ensure functionality and persistence of job states across instances.
• Implemented migration generation for SQLite, enabling users to create necessary database tables easily.
• Updated documentation to include instructions for setting up the SQLite backend.
• Enhanced existing test frameworks to support SQLite integration testing.

closes: #126
closes: #398

[Copilot]

Pull request overview

Adds a new local durable SQLite backend to Karya (queue-store + backend wrapper), plus migration generation (ActiveRecord + Sequel), framework-level delegation helpers, and integration/e2e coverage to validate end-to-end behavior and persistence guarantees.

Changes:

• Introduces Karya::QueueStore::SQLite and Karya::Backend::SQLite, with a shared SQLite schema catalog and durable state snapshot persistence.
• Adds SQLite migration installers for Karya::ActiveRecord and Karya::Sequel, and exposes delegated install_sqlite_migration helpers in Rails/Roda/Sinatra/Hanami integrations.
• Expands docs and test/support infrastructure to exercise SQLite in unit, integration, and e2e flows.

Reviewed changes

Copilot reviewed 48 out of 52 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
spec/support/sqlite_e2e_support.rb	Adds tmp SQLite DB helper and Sequel URL adapter for e2e tests.
spec/support/framework_sql_backend_support.rb	Adds with_sqlite_backend helper for framework integration specs.
gems/karya-sinatra/spec/karya/sinatra_sqlite_e2e_spec.rb	Adds Sinatra e2e coverage for SQLite backend + migration application.
gems/karya-sinatra/spec/karya/sinatra_spec.rb	Adds unit spec asserting SQLite migration delegation.
gems/karya-sinatra/sig/karya/sinatra.rbs	Types new install_sqlite_migration API surface.
gems/karya-sinatra/lib/karya/sinatra.rb	Delegates SQLite migration installation to Karya::Sequel.
gems/karya-sinatra/Gemfile.lock	Adds sqlite3 dependency resolution for Sinatra gem tests.
gems/karya-sinatra/Gemfile	Adds sqlite3 gem dependency.
gems/karya-roda/spec/karya/roda_sqlite_e2e_spec.rb	Adds Roda e2e coverage for SQLite backend + migrations.
gems/karya-roda/spec/karya/roda_spec.rb	Adds unit spec asserting SQLite migration delegation.
gems/karya-roda/sig/karya/roda.rbs	Types new install_sqlite_migration API surface.
gems/karya-roda/lib/karya/roda.rb	Delegates SQLite migration installation to Karya::Sequel.
gems/karya-roda/Gemfile.lock	Adds sqlite3 dependency resolution for Roda gem tests.
gems/karya-roda/Gemfile	Adds sqlite3 gem dependency.
gems/karya-rails/spec/karya/rails_sqlite_e2e_spec.rb	Adds Rails e2e coverage for SQLite backend + AR migration execution.
gems/karya-rails/spec/karya/rails_spec.rb	Adds unit spec asserting SQLite migration delegation.
gems/karya-rails/sig/karya/rails.rbs	Types new install_sqlite_migration API surface.
gems/karya-rails/lib/karya/rails.rb	Delegates SQLite migration installation to Karya::ActiveRecord.
gems/karya-hanami/spec/karya/hanami_sqlite_e2e_spec.rb	Adds Hanami e2e coverage for SQLite backend + migrations.
gems/karya-hanami/spec/karya/hanami_integration_spec.rb	Adds unit/integration spec asserting SQLite migration delegation.
gems/karya-hanami/sig/karya/hanami.rbs	Types new install_sqlite_migration API surface.
gems/karya-hanami/lib/karya/hanami.rb	Delegates SQLite migration installation to Karya::Sequel.
gems/karya-hanami/Gemfile.lock	Adds sqlite3 dependency resolution for Hanami gem tests.
gems/karya-hanami/Gemfile	Adds sqlite3 gem dependency.
docs/pages/backends.md	Documents how to add sqlite3 gem and configure the SQLite backend.
core/karya/spec/karya/sequel_spec.rb	Adds coverage for Sequel SQLite migration generation and default name fallback.
core/karya/spec/karya/queue_store/sq_lite_spec.rb	Adds unit coverage for SQLite queue-store behavior, persistence, and failure handling.
core/karya/spec/karya/backend/sq_lite_spec.rb	Adds backend wrapper tests including dependency load errors and option validation.
core/karya/spec/karya/active_record_spec.rb	Adds coverage for ActiveRecord SQLite migration generation and default name fallback.
core/karya/spec/e2e/karya/cli_worker_sqlite_spec.rb	Adds CLI worker e2e coverage for SQLite backend boot + execution.
core/karya/sig/karya/sequel.rbs	Types new install_sqlite_migration on Karya::Sequel.
core/karya/sig/karya/queue_store/sqlite/internal/state_codec.rbs	Types SQLite state codec snapshot encode/decode surface.
core/karya/sig/karya/queue_store/sqlite/internal/persistence_mutex.rbs	Types SQLite persistence mutex and synchronization boundary.
core/karya/sig/karya/queue_store/sqlite/internal/dependency_loader.rbs	Types SQLite dependency loader (require_sqlite3!).
core/karya/sig/karya/queue_store/sqlite.rbs	Adds RBS for SQLite queue-store public surface (needs completion for nested constants).
core/karya/sig/karya/internal/sqlite_schema_catalog.rbs	Types shared SQLite schema catalog and migration renderers.
core/karya/sig/karya/backend/sqlite.rbs	Types Karya::Backend::SQLite.
core/karya/sig/karya/backend.rbs	Extends backend union to include SQLite.
core/karya/sig/karya/active_record.rbs	Types new install_sqlite_migration on Karya::ActiveRecord.
core/karya/lib/karya/sequel.rb	Implements Sequel SQLite migration generator using shared schema catalog.
core/karya/lib/karya/queue_store/sqlite/internal/state_codec.rb	Implements SQLite durable state encoding/decoding.
core/karya/lib/karya/queue_store/sqlite/internal/persistence_mutex.rb	Implements SQLite transactional synchronization + schema bootstrap.
core/karya/lib/karya/queue_store/sqlite/internal/dependency_loader.rb	Implements sqlite3 gem loading with actionable LoadError messaging.
core/karya/lib/karya/queue_store/sqlite/internal.rb	Wires SQLite queue-store internal components.
core/karya/lib/karya/queue_store/sqlite.rb	Implements SQLite queue store (URL parsing, connection mgmt, persistence, fork handling).
core/karya/lib/karya/queue_store.rb	Autoloads Karya::QueueStore::SQLite.
core/karya/lib/karya/internal/sqlite_schema_catalog.rb	Adds shared SQLite schema DDL + migration template rendering.
core/karya/lib/karya/backend/sqlite.rb	Implements SQLite backend wrapper that builds the SQLite queue store.
core/karya/lib/karya/backend.rb	Autoloads Karya::Backend::SQLite.
core/karya/lib/karya/active_record.rb	Implements ActiveRecord SQLite migration generator using shared schema catalog.
core/karya/Gemfile.lock	Adds sqlite3 dependency resolution for core package tests.
core/karya/Gemfile	Adds sqlite3 gem dependency.