feat(primitives): create torrust-net-primitives and move ServiceBinding (#1797)

[josecelano]

Moves ServiceBinding out of torrust-tracker-primitives into a new dedicated
torrust-net-primitives crate. torrust-server-lib now depends on
torrust-net-primitives instead of torrust-tracker-primitives, breaking an
unnecessary coupling between a generic server utility and tracker-specific types.

Motivation

The coupling analysis (F-04 in EPIC #1669) found that torrust-server-lib
depended on torrust-tracker-primitives solely to import ServiceBinding — a
struct representing a network address binding. torrust-server-lib has no
tracker-specific concerns; pulling in the entire torrust-tracker-* primitives
crate for one generic networking type is wasteful and semantically misleading.

ServiceBinding is a generic concept reusable across the Torrust organisation,
not just the tracker. A dedicated torrust-net-primitives crate makes the type
available to any Torrust project without a torrust-tracker-* dependency.

Changes

New crate

• packages/net-primitives/ — new torrust-net-primitives crate (publish = true)
  • src/service_binding.rs — ServiceBinding and Protocol (moved from packages/primitives/)
  • src/lib.rs — exports pub mod service_binding
  • README.md

Updated workspace root

• Cargo.toml — added packages/net-primitives to [workspace] members
• Cargo.lock — updated

Updated packages (Cargo.toml + import paths)

• packages/primitives/ — removed service_binding module definition; added
  #[deprecated] re-export from torrust_net_primitives for external crates.io
  consumer backwards compatibility (same pattern as DurationSinceUnixEpoch and
  AnnouncePolicy)
• packages/server-lib/ — replaced torrust-tracker-primitives dep with
  torrust-net-primitives (ServiceBinding was its only use)
• packages/axum-health-check-api-server/, packages/axum-http-tracker-server/,
  packages/axum-rest-tracker-api-server/, packages/http-tracker-core/,
  packages/tracker-client/, packages/udp-tracker-core/,
  packages/udp-tracker-server/ — added torrust-net-primitives dep; updated
  all import paths from torrust_tracker_primitives::service_binding to
  torrust_net_primitives::service_binding across ~45 source files

Docs

• docs/issues/open/1797-1669-05-create-torrust-net-primitives-and-move-service-binding.md — spec
• docs/issues/open/1669-overhaul-packages/EPIC.md — SI-05 updated to reference Create torrust-net-primitives and move ServiceBinding from torrust-tracker-primitives #1797
• docs/issues/open/1669-overhaul-packages/workspace-coupling-report.md — regenerated

Validation

Check	Result
cargo build --workspace	✅ clean
cargo test --workspace	✅ all pass
linter all	✅ exit code 0
cargo machete	✅ no unused deps
cargo +nightly fmt --check	✅ pass
cargo +nightly check --workspace --all-targets	✅ pass
cargo +nightly doc --no-deps --workspace	✅ pass
grep "torrust_tracker_primitives::.*ServiceBinding" --include="*.rs" -r .	✅ zero matches
grep "torrust-tracker-primitives" packages/server-lib/Cargo.toml	✅ zero matches

Closes #1797

Part of #1669 (SI-05)

[Copilot]

Pull request overview

Extracts ServiceBinding (and Protocol) from torrust-tracker-primitives into a new dedicated torrust-net-primitives crate, breaking the unnecessary coupling between torrust-server-lib and tracker-specific primitives.

Changes:

• New packages/net-primitives crate (publish = true) hosting service_binding module (moved from packages/primitives).
• packages/primitives keeps a #[deprecated] re-export of service_binding for crates.io backwards compatibility.
• All workspace consumers (server-lib, axum servers, http/udp tracker core/server, tracker-client) updated to import from torrust_net_primitives::service_binding; server-lib no longer depends on torrust-tracker-primitives.

Reviewed changes

Copilot reviewed 53 out of 54 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
packages/net-primitives/{Cargo.toml,README.md,src/lib.rs,src/service_binding.rs}	New crate scaffolding and moved module
packages/primitives/{Cargo.toml,src/lib.rs}	Drop module, add #[deprecated] re-export, depend on net-primitives
packages/server-lib/{Cargo.toml,src/registar.rs,src/signals.rs}	Swap dep and imports
packages/{axum-health-check-api-server,axum-http-tracker-server,axum-rest-tracker-api-server,http-tracker-core,udp-tracker-core,udp-tracker-server,tracker-client}/**	Add dep and update imports
Cargo.toml, Cargo.lock	Workspace members and lockfile updates
docs/issues/open/1797-*, docs/issues/open/1669-overhaul-packages/{EPIC.md,workspace-coupling-report.md}	Spec promoted to open, EPIC updated, coupling report regenerated

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[Copilot]

Pull request overview

Copilot reviewed 54 out of 55 changed files in this pull request and generated no new comments.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 29 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.69%. Comparing base (ca97cce) to head (88de3d5).

Files with missing lines	Patch %	Lines
.../dev-tools/analysis/workspace-coupling/src/main.rs	0.00%	29 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #1799      +/-   ##
===========================================
+ Coverage    77.64%   77.69%   +0.04%     
===========================================
  Files          379      379              
  Lines        28602    28607       +5     
  Branches     28602    28607       +5     
===========================================
+ Hits         22209    22226      +17     
+ Misses        6080     6072       -8     
+ Partials       313      309       -4     

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[josecelano]

ACK 88de3d5