Extract Git hook logic into fast-forward/git-hooks package

[coisa]

Objective

Extract the Git hook payloads and supporting hook-specific runtime logic from fast-forward/dev-tools into a dedicated fast-forward/git-hooks package.

Current Limitation

fast-forward/dev-tools currently owns the packaged hook templates, placeholder rendering, DevTools-specific config-path resolution, and installation workflow for Git hooks. That coupling makes the hook surface harder to evolve independently, prevents reuse outside DevTools, and keeps hook-specific packaging concerns mixed into a broader automation package.

Proposed Work

Create a focused fast-forward/git-hooks repository/package that owns the packaged hook payloads and the hook-specific runtime support currently embedded in DevTools. fast-forward/dev-tools should become a consumer and orchestrator of that package instead of the canonical home for hook internals.

The extraction may evaluate fast-forward/composer-installers when it helps standardize installation paths or package layout, but the initiative should not depend on adopting it unless it clearly simplifies the integration.

Scope

• Define the package boundary between fast-forward/dev-tools and fast-forward/git-hooks.
• Move packaged Git hook templates and their dedicated rendering/path-resolution support into the extracted package.
• Update DevTools to consume the extracted package during git-hooks and dev-tools:sync flows.
• Preserve the current GrumPHP behavior where hooks prefer a project-local grumphp.yml and otherwise use the managed packaged fallback.

Non-goals

• Extract unrelated sync assets such as workflows, CODEOWNERS, licenses, docs scaffolding, or other consumer automation payloads in the same initiative.
• Redesign the supported Git hook behavior beyond what is required to complete the extraction safely.
• Require fast-forward/composer-installers adoption if the extraction can stay simpler without it.

Acceptance Criteria

Delivery Criteria

• A dedicated fast-forward/git-hooks package boundary is defined with explicit integration points for DevTools.
• Packaged hook payloads and hook-specific rendering/path-resolution logic are moved out of fast-forward/dev-tools into the extracted package.
• fast-forward/dev-tools consumes the extracted package for git-hooks and dev-tools:sync orchestration instead of owning the hook internals directly.
• Local and global DevTools installations continue producing working hooks, including project-local grumphp.yml preference and packaged fallback behavior.
• Focused tests are added or updated around the extracted boundaries and compatibility behavior.
• Documentation and release notes are updated where the package split changes maintainer or consumer expectations.

Architectural / Isolation Criteria

• MUST: The core logic MUST be isolated into dedicated classes or services instead of living inside command or controller entrypoints.
• MUST: Responsibilities MUST be separated across input resolution, domain logic, processing or transformation, and output rendering when the change is non-trivial.
• MUST: The command or controller layer MUST act only as an orchestrator.
• MUST: The implementation MUST avoid tight coupling between core behavior and CLI or framework-specific I/O.
• MUST: The design MUST allow future extraction or reuse with minimal changes.
• MUST: The solution MUST remain extensible without requiring major refactoring for adjacent use cases.
• MUST: Argument and option resolution MUST be validated separately from command execution logic.
• MUST: Console formatting and rendering MUST stay separate from domain processing.
• MUST: Exit behavior, error messaging, and generated output MUST remain deterministic and testable.