Add asset versioning, dynamic static base and centralized template rendering

[dissenter-web]

Motivation

• Introduce cache-busting and flexible static asset paths so updated assets are reliably loaded across deployments.
• Reduce duplication when rendering templates by centralizing common context like asset_version and request.
• Use url_for for static asset URLs in templates to ensure correct URL construction.

Description

• Add ASSET_VERSION environment variable and expose it to templates via a new render_template helper that injects asset_version into every response in app/main.py.
• Replace direct templates.TemplateResponse(...) calls with render_template(...) across route handlers.
• Add data attributes data-static-base and data-asset-version to the root HTML element in templates/base.html and include ?v={{ asset_version }} query params on CSS/JS static includes.
• Update client JS (static/js/layout.js, static/js/project.js, static/js/theme.js) to compute a dynamic staticBase from the page attribute and append the assetVersion to fetch and CSS links for cache-busting; update theme link generation to include both assetVersion and a timestamp.
• Replace hard-coded /static/... image/script paths in templates with url_for('static', path=...) calls and add versioning to script tags; add logo path update in header and project script include.

Testing

• Ran the project test suite with pytest and all tests passed.
• Ran flake8 linting checks and no new issues were reported.

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Codex Task