Add `created_at: Option<DateTime<Utc>>` through all layers so CLI users
can backdate entities at creation/update time. When omitted, falls back
to `Utc::now()`.
- Domain: add field to all New*/Update* structs with serde(default)
- Domain: timeline events use entity created_at instead of Utc::now()
- Repos: unify INSERT to explicit Rust-side created_at with unwrap_or_else
- Repos: add created_at to UPDATE dynamic query builders
- Routes: add field to submission structs and has_changes guards
- Clients: pass created_at through manual JSON client methods
- CLI: add --created-at flag with parse_created_at helper (RFC 3339 or YYYY-MM-DD)
- Add migration 0016 to drop notes column from roasters table
- Remove notes from domain structs, repositories, views, CLI, routes
- Remove notes from AI extraction prompts and ExtractedRoaster struct
- Remove notes from scan page form and submission handler
- Update templates, bootstrap script, backup module, and tests
- Add push_update_field! macro to reduce UPDATE query boilerplate
- Rename sort_clause() to order_clause() for consistency
- Convert bags.rs update method from string concatenation to QueryBuilder
- Apply macro to roasters.rs, roasts.rs, and bags.rs update methods
This reduces ~100 lines of repetitive code and ensures consistent
patterns for building dynamic UPDATE queries across all repositories.
