Seed from go-template-repo, renamed to simplexcalc

The template's files at a77fd30, without its history or LICENSE, after
script/rename simplexcalc.

Model: opus-5-5

.dockerignore

@@ -0,0 +1,26 @@
+# Never exclude Go sources, go.mod, go.sum or .golangci.yml: the lint
+# and test stages only ever examine what reaches the build context, and
+# an exclusion here makes them pass over a tree that is missing a
+# package. script/assert-context-complete exists to catch exactly that,
+# and will fail the build rather than let it happen silently.
+.git/
+.gitea/
+bin/
+data/
+AGENTS.md
+README.md
+docs/
+LICENSE
+.editorconfig
+.prettierrc
+.prettierignore
+.env
+.env.*
+*.db
+*.sqlite
+*.sqlite3
+.DS_Store
+.idea/
+.vscode/
+tmp/
+temp/