Build the Kirjaa log flow and Historia list

Stage 1's point is collecting eating history, so the logging path is the one
that has to be frictionless: pick a dish, tick sides, done.

Kirjaa:
- dishes ordered and sized by how often they have been eaten, so the likely
  answer is the biggest target on the screen
- picking a dish opens the sides step; a dish with has_sides false says so
  instead of offering an empty list
- saving redirects, so a refresh cannot double-post
- a day already logged shows the entry with edit and delete. Editing reopens
  the sides step with the existing sides ticked, which makes editing and
  creating the same screen
- day switcher and a server-side search over the catalog

Historia walks back day by day to the oldest entry, so a day nobody wrote
down appears as an explicit gap rather than quietly missing.

No JavaScript is involved: every interaction is a link or a form, and the
checked-chip styling is :has(input:checked). Datastar stays loaded but unused
until an interaction genuinely needs to avoid a page load.

Also fix a Makefile ordering bug: lint did not depend on generate, so `go vet`
could run against templ output that was being rewritten. check now runs its
phases as sub-makes so `make -j` cannot interleave them.

Records two features that are specified but not built: dish CRUD in the UI
(§7.3, only import exists today) and a per-device light/dark switch (§7.4).
The switch must show the state that is active, not the one clicking produces.

PRD.md

@@ -200,6 +200,22 @@ regenerates or swaps.
 - Settings page for the cooldown window (default **14 days**, configurable).
   *(Stage 2 — only relevant once the suggester exists.)*
 
+### 7.4 Appearance (stage 1)
+
+- A light / dark theme switch, remembered **per device**. The instance is
+  shared and has no accounts, so this is a device preference in
+  `localStorage`, never a server-side setting — the phone in the kitchen and
+  the laptop must be able to disagree.
+- Three states: light, dark, and follow the system. System is the default.
+- The control **shows the state that is currently active**, not the state
+  clicking it would produce. A segmented control with the active option
+  marked, not a single button labelled with its opposite. A lightswitch does
+  not read "off" while the lights are on.
+- Implementation is `color-scheme` on the root element: `light dark` for the
+  system-following default, `only light` or `only dark` when overridden.
+  Because the palette is built from `light-dark()` custom properties, no
+  other CSS changes.
+
 ## 8. Suggestion algorithm (stage 2)
 
 Produce seven mains, then attach sides per meal.