Move `AnnouncePolicy` from `torrust-tracker-configuration` to `torrust-tracker-primitives`

[josecelano]

Goal

Move the AnnouncePolicy struct from torrust-tracker-configuration into torrust-tracker-primitives, reversing an inverted dependency where a primitives package depends on a configuration package. After the move, torrust-tracker-configuration depends on torrust-tracker-primitives for AnnouncePolicy, which is the natural direction.

Background

AnnouncePolicy (min/max announce intervals) is a domain concept — it describes the peer communication policy for the BitTorrent announce cycle. Domain concepts belong in primitives, not in configuration, which should be concerned only with config-file parsing and environment variable wiring.

The coupling analysis (F-03) found that torrust-tracker-primitives imports torrust_tracker_configuration::AnnouncePolicy — meaning a primitives package depends on a configuration package. This is an inverted dependency: primitives should sit at the bottom of the dependency graph, with configuration depending on it, not the reverse.

Moving AnnouncePolicy to primitives fixes the inversion:

• Before: primitives → configuration (for AnnouncePolicy)
• After: configuration → primitives (for AnnouncePolicy, among other types)

Both packages are published to crates.io. Removing AnnouncePolicy from torrust-tracker-configuration is a semver breaking change for that crate; it will require a major version bump when published. Within this workspace, at version 3.0.0-develop, the change is expected and planned.

This is subissue SI-04 of EPIC #1669 (Overhaul: Packages).

Scope

In Scope

• Move the AnnouncePolicy struct (and any directly associated types or impl blocks) from packages/configuration/src/ to packages/primitives/src/announce.rs.
• Remove torrust-tracker-configuration as a dependency of torrust-tracker-primitives; torrust-tracker-primitives must not depend on torrust-tracker-configuration.
• Update packages/configuration to import AnnouncePolicy from torrust-tracker-primitives; keep a #[deprecated] re-export in configuration for external consumers.
• Update all other workspace files that import AnnouncePolicy from torrust_tracker_configuration to import it from torrust_tracker_primitives.
• Remove torrust-tracker-configuration from packages/http-protocol/Cargo.toml (only usage was AnnouncePolicy in test code).
• Verify the workspace builds and all tests pass.

Out of Scope

• Any rename of AnnouncePolicy or changes to its fields.
• Publishing a new crates.io version; the semver bump is handled in the release cycle.
• Extracting torrust-tracker-primitives to a standalone repository (a later subissue).

Implementation Plan

ID	Task
T1	Locate all definition and usage sites of AnnouncePolicy across the workspace
T2	Move AnnouncePolicy definition to packages/primitives/src/announce.rs
T3	Remove AnnouncePolicy from packages/configuration/src/; add deprecated re-export pointing to torrust_tracker_primitives
T4	Add torrust-tracker-primitives as a dep of packages/configuration/Cargo.toml
T5	Remove torrust-tracker-configuration dep from packages/primitives/Cargo.toml
T6	Update all workspace files that import AnnouncePolicy from torrust_tracker_configuration to use torrust_tracker_primitives
T7	Remove torrust-tracker-configuration from packages/http-protocol/Cargo.toml
T8	Run cargo build --workspace and cargo test --workspace
T9	Run linter all and cargo machete

Acceptance Criteria

• packages/primitives/src/announce.rs defines AnnouncePolicy and exports it publicly.
• packages/primitives/Cargo.toml does not list torrust-tracker-configuration as a dependency.
• packages/configuration/src/ no longer defines AnnouncePolicy; it re-exports from torrust-tracker-primitives with a deprecation notice.
• No workspace file imports AnnouncePolicy from torrust_tracker_configuration directly (all use torrust_tracker_primitives).
• cargo build --workspace succeeds with zero errors.
• cargo test --workspace passes with zero failures.
• linter all exits with code 0.
• cargo machete reports no unused dependencies.

Part of EPIC #1669.