chore: add mise tasks to run the app locally

mise run dev installs deps, starts Postgres, then runs Flask and Vite together.

mise.toml

@@ -1,3 +1,33 @@
 [tools]
 python = "3.14"
 node = "24"
+
+[tasks.setup]
+description = "Create the venv and install backend and frontend dependencies"
+# ponytail: reinstalls on every run (fast when up to date); add sources/outputs if it ever gets slow
+run = [
+  "python -m venv .venv",
+  ".venv/bin/pip install -q --disable-pip-version-check -r backend/requirements.txt",
+  "npm install --no-fund --no-audit",
+]
+
+[tasks.db]
+description = "Start local Postgres and wait until it accepts connections"
+run = [
+  "docker compose up -d db",
+  "until docker compose exec -T db pg_isready -q -U postgres; do sleep 1; done",
+]
+
+[tasks."dev:api"]
+description = "Flask API on :5000"
+depends = ["setup", "db"]
+run = ".venv/bin/python backend/app.py"
+
+[tasks."dev:web"]
+description = "Vite UI; /api is proxied to Flask"
+depends = ["setup"]
+run = "npm run dev"
+
+[tasks.dev]
+description = "Start the app for local testing (API + UI)"
+depends = ["dev:api", "dev:web"]