feat: Establish initial project structure and dependencies

[apenlor]

Lab Phase & Objective

This PR establishes the foundational repository structure, build system, and workflow required to begin Phase 1: The Standalone Secure Monolith. It does not implement the phase's acceptance criteria but creates the stable base upon which they will be built.

Key Architectural Decisions & Trade-offs

• Maven Multi-Module Project: Adopted a parent POM at the root to provide centralized dependency management (via <dependencyManagement>) and a unified build command (./mvnw clean verify). This ensures version consistency across all current and future modules.
• Maven Wrapper (mvnw): Included and configured to ensure a hermetic, reproducible build environment. This decouples the build process from any locally installed Maven version and guarantees consistency between local, CI, and Docker builds.
• PR-Based Workflow: Established a mandatory PR-based workflow by enabling branch protection on main. This enforces our quality gates from the very first line of code.
• PR Template & Conventional Commits: Added a detailed PR template and committed to the Conventional Commits specification to ensure a high-quality, auditable, and semantic Git history.

Verification Strategy

• Unit/Integration Tests: All new and existing tests pass via ./mvnw clean verify. (The command completes successfully with no tests to run).
• Docker Compose: N/A for this foundational PR. Will be introduced in the next PR.
• Manual Verification: N/A. No runnable application yet.

Definition of Done Checklist

• The PR title follows the Conventional Commits specification (e.g., feat: ..., fix: ...).
• The code adheres to SOLID principles and project conventions.
• The README.md has been updated to reflect the new state of the project.
• All new logic is covered by automated tests. (Test framework is in place).
• Security implications of the changes have been considered (secure workflow established).
• Observability implications (metrics, logs, traces) have been considered. (N/A for this change).