Fully migrate from compile-time maud templates to runtime Tera:
- Rewrote main.rs to use TemplateEngine and discover_sections()
- Replaced hardcoded blog/projects with generic section loop
- Added Clone derive to Frontmatter and Content
- Fixed section_type dispatch via Section struct
- Deleted src/templates.rs, removed maud dependency
Users can now add sections without code changes.
Lay groundwork for user-editable templates by adding Tera as a
runtime template engine alongside the existing maud templates.
Changes:
- Add tera dependency
- Create TemplateEngine struct with render methods
- Add TemplateLoad/TemplateRender error variants
- Add section_type/template fields to Frontmatter
- Create templates/ directory with base, page, section, and content templates
Dead code warnings are expected; TemplateEngine will be wired
in to replace maud in subsequent commits.
