Finalize 0.3.1: dependency refresh, structural cleanup, and release docs polish

[orenlab]

Patch release focused on dependency refresh, structural cleanup, and release polish.

Security And Reliability

• Refreshed runtime and development dependencies, including security-driven updates, and regenerated uv.lock.
• Tightened callback, Docker, logging, and runtime guard paths; improved several reliability edge cases surfaced by CI
  and static analysis.

Quality And Maintainability

• Reduced structural duplication across core handlers, Docker update flows, utilities, and tests.
• Raised the default codeclone grade to B and expanded regression coverage around the refactors.

Release And Docs

• Bumped the project, sample config, docs, and Docker exact-tag references to 0.3.1.
• Updated Docker Hub and release-facing documentation to match the supported stable-image contract.

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

View in Codacy

🟢 Metrics 0 complexity · 0 duplication

Metric	Results
Complexity	0
Duplication	0

View in Codacy

_{NEW Get contextual insights on your PRs based on Codacy's metrics, along with PR and Jira context, without leaving GitHub. Enable AI reviewer
TIP This summary will be updated as you push new changes.}

[sonarqubecloud]

Quality Gate passed

Issues
14 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud