score/time_daemon: Create AoU requirements

> [!IMPORTANT]
> Link the implementing PR to this issue by including `Closes #81` in the PR description or commit message.

### What

Write the Assumption of Use requirements for `score/time_daemon`, capturing all deployment and startup preconditions that integrators must fulfil.

TimeDaemon will likely run as an ASIL-B application. Its deployment preconditions must be formally specified so that integrators can verify them. Examples: gPTP daemon must be running and reachable before TimeDaemon starts; required shared memory permissions must be in place; IPC channel path must be pre-configured. Author as `aou_req` nodes at `score/time_daemon/docs/requirements/time_daemon_aou.rst`.

### Acceptance Criteria

- [ ] `score/time_daemon/docs/requirements/time_daemon_aou.rst` created
- [ ] All startup/deployment preconditions captured as `aou_req` nodes with `:status: valid`
- [ ] Every `aou_req` links back to the relevant `comp_req` it restricts

### References

- [S-CORE Requirements Engineering](https://eclipse-score.github.io/process_description/main/process_areas/requirements_engineering/)