refactor!: rename to org.sqlcj and license under Apache 2.0

[omer-cengel]

Summary

Gives sqlcj its permanent identity before any public coordinate is created under the old name: every Java package, Maven coordinate, and CLI main class moves from dev.sqlcj to org.sqlcj, the project is licensed under the Apache License, Version 2.0, and the security policy points at the sqlcj GitHub organization.

Changes

• Move all CLI and runtime sources and tests from dev.sqlcj to org.sqlcj, including the fully qualified schema types in query analysis and the runtime references the generator emits.
• Change the Maven groupId to org.sqlcj in the reactor and the external sample, and start the CLI from org.sqlcj.Main in the JAR manifest, the shaded JAR, and the exec plugin.
• Update the release verification script's staged-artifact path, the root configuration's example package, and the sample application's imports.
• Update the README, quickstart, query, and PostgreSQL documentation to the new package, coordinate, and main class.
• Add the Apache License, Version 2.0, as the root LICENSE, state it in a new README License section, and remove the claim that no license exists.
• Point the private vulnerability reporting link at https://github.com/sqlcj/sqlcj.

Scope and non-goals

• No behavior changes: generated SQL, parameter order, selected-column order, binding, and the generated API are unchanged apart from the runtime package name, and the runtime keeps no dependencies.
• No compatibility alias for dev.sqlcj; sources generated by an earlier build must be regenerated against org.sqlcj:sqlcj-runtime.
• The GitHub organization rename happens on GitHub, outside this change.
• License headers in source files, POM license metadata, and anything on the sqlcj.org domain are not part of this change.