Create feature architecture for Time in score/ repo

> [!IMPORTANT]
> Link the implementing PR to this issue by including `Closes #85` in the PR description or commit message.

### What

Write the feature-level architecture document for the Time feature in the `score/` repository.

Create `score/docs/features/time/architecture/index.rst` in the `score/` repository. This document shows the feature's public interface boundary, external actors, and end-to-end behaviour — not a component's internals.

- **`feat_arc_sta` directive** (static view): the Time feature's logical interface structure — the `score::time` API, the IPC channel between module components, the gPTP IPC (between TimeSlave and the gPTP daemon), and the PHC hardware interface.
- **`feat_arc_dyn` directive** (dynamic view): the end-to-end synchronization sequence: `gPTP HW → TimeSlave → ts_client SHM → TimeDaemon → IPC → Application via Clock`.

Every directive must link to feature requirements via `:fulfils: feat_req__time__` and have `:status: valid`.

### Acceptance Criteria

- [ ] `feat_arc_sta` and `feat_arc_dyn` directives present in `score/docs/features/time/architecture/`
- [ ] Feature architecture references the `time` module as implementing the time feature
- [ ] `:fulfils:` links to valid `feat_req__time__*` UIDs

### References

- [S-CORE Architecture Design](https://eclipse-score.github.io/process_description/main/process_areas/architecture_design/guidance/architecture_guideline.html)