docs: teach the tour and the runbooks about flask

docs/runbook/add-an-adapter.md

@@ -17,6 +17,8 @@ ADAPTER_ROLE="api"          # web, api, or app
 ADAPTER_TIER="B"
 ADAPTER_LANGUAGE="go"       # "typescript" opts into packages/types
 ADAPTER_GENERATOR='<the framework's own generator, writing into "$APP_DIR">'
+                            # no generator? the package manager's project
+                            # init: adapters/flask uses `uv init --bare`
 # ADAPTER_POST_GENERATE='<one-time fixup for a real generator bug>'
 ```
 
@@ -26,11 +28,19 @@ generator itself gets wrong: `adapters/nestjs/adapter.env` sets it to
 un-await `bootstrap()` and run prettier once. Only reach for it once
 you've hit a real generator bug — it's a patch, not a default step.
 
+The exception is a stack whose generator writes only a manifest: there the
+dependencies are ordinary setup rather than a fixup, and `adapters/flask`
+uses this field to `uv add` them. Either way it ends in a `grep` that fails
+loudly, so a generator that reports success while writing nothing becomes a
+build failure rather than an `ImportError` at container start.
+
 ## 3. Write `mise.toml`
 
 All nine contract tasks. Declare the language in a local `[tools]` block so
-it never reaches the project root. `format`, `lint`, and `check` must not
-write.
+it never reaches the project root — or, where the language's own tooling
+owns the pin, declare the tool and let it read that pin (`adapters/flask`
+pins `uv` and leaves python to `.python-version`). `format`, `lint`, and
+`check` must not write.
 
 ## 4. Write `Dockerfile`, `.env.example`, `lefthook.fragment.yml`
 

docs/runbook/bump-a-toolchain-version.md

@@ -9,6 +9,11 @@
 - One adapter's own language (`php`'s Composer, or the pinned Node used by
   `laravel-inertia`'s build step): that adapter's own `mise.toml`, e.g.
   `adapters/laravel-api/mise.toml`.
+- `flask`'s python is the exception, and searching the `[tools]` blocks for
+  it finds nothing: `adapters/flask/mise.toml` pins `uv` only, and the
+  interpreter is pinned in `adapters/flask/.python-version`, the file uv
+  reads. Bumping it means editing that file and the `--python` argument in
+  `adapters/flask/adapter.env`, which sets `requires-python` at generation.
 
 ## 2. Edit the version
 

docs/tour/01-toolchain.md

@@ -16,6 +16,10 @@ and, in a generated project, `common/mise.root.toml`'s (`node`, `pnpm`,
   any adapter.
 - `adapters/laravel-api/mise.toml` — a language declared in a local
   `[tools]` block so it never reaches the project root (see 08 — Adapters).
+- `adapters/flask/mise.toml` — the same rule with the pin somewhere else
+  again: it declares `uv` and no python, because uv resolves its own managed
+  interpreter and would install a mise-pinned one only to ignore it.
+  `adapters/flask/.python-version` is the file uv actually reads.
 - Upstream for comparison: immich's own root
   `https://github.com/immich-app/immich/blob/351be95/mise.toml`, which pins
   every service's language in one place — the opposite of this project's

docs/tour/08-adapters.md

@@ -4,7 +4,10 @@
 
 An adapter is an overlay, not a vendored application: `scaffold` invokes a
 framework's own generator (`create-next-app`, `nest new`, `composer
-create-project`) and then copies its own files on top of the result.
+create-project`) and then copies its own files on top of the result. Where a
+framework ships no generator, the package manager's project init stands in —
+`flask` runs `uv init --bare`, which writes a `pyproject.toml` and nothing
+else, and the overlay supplies the application itself.
 `lib/lint.sh` requires four of them — `adapter.env`, `mise.toml`,
 `Dockerfile`, `.env.example` — and an adapter may ship more: `nextjs` adds
 `next.config.ts` and `.prettierignore`, `laravel-api` adds `phpstan.neon`