Initial commit: PRD, build tooling, and design mockups

Foodster is a self-hosted dinner log and meal suggester for one household.
Stage 1 (eating history) is in development; stage 2 (the suggester) follows
once there is enough history to weight against.

Replace the PRD's original stack (Nuxt, Postgres, Drizzle, Pico CSS) with
Go 1.27, net/http, templ, Datastar and SQLite — one static binary, no
Node.js in the build. Sections 3, 4, 5, 9, 10 and 11 are rewritten to match.

Record the decisions made while reviewing mockups:

- the UI is written in Finnish; PRD, code and comments stay English
- access is one shared password over HTTP Basic rather than open on the LAN
- images are CalVer vYYYYMMDD-N, built with Podman, run under Docker Compose
- registry coordinates live in .env, so no infrastructure detail is
  committed and the MIT publication option stays open

mockups/ holds standalone HTML design studies. log-fi.html is the current
one; the others are superseded exploration kept for reference.

.gitignore

@@ -0,0 +1,13 @@
+# Local config — holds the registry hostname and the shared password.
+.env
+
+# Build output
+/foodster
+
+# Generated by `templ generate` during the container build.
+*_templ.go
+
+# Local database
+*.db
+*.db-shm
+*.db-wal