🐛 Fix consumer CI lint and update shared workflows

[turtton]

Problem

ShuttlePub/workflows consumer CI checks Emumet main with cargo clippy --all-targets -- -D warnings. Emumet's own CI was pinned to older reusable workflows that did not lint test targets, so test-code warnings made all four consumer jobs fail.

Changes

• Fix test-target Clippy findings in kernel, application, server, and driver without suppressing lints.
• Pin Emumet's check, PostgreSQL check, and coverage reusable workflows to the current ShuttlePub/workflows main commit 5be8e4cbb4f1f1616dc88316d469f3b13b059445.

Verification

• cargo clippy --workspace --all-targets -- -D warnings — passed with Rust 1.97.0.
• cargo fmt --all -- --check — passed.
• cargo test --quiet -p kernel -p application — passed (227 passed, 45 ignored).
• git diff --check — passed.

The PR CI will verify the PostgreSQL, server, and coverage jobs. Once merged, the four ShuttlePub/workflows Renovate PR consumer runs can be rerun against the corrected Emumet main.

[codecov]

Codecov Report

❌ Patch coverage is 62.50000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 75.47%. Comparing base (a34f524) to head (5bf4250).

Files with missing lines	Patch %	Lines
kernel/src/entity/profile_transfer_request.rs	57.14%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #63   +/-   ##
=======================================
  Coverage   75.47%   75.47%           
=======================================
  Files         232      232           
  Lines       27216    27216           
=======================================
  Hits        20542    20542           
  Misses       6674     6674           

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