fix: cap Objecten/Objecttypen uWSGI to 1 worker — unstarve verify-stack e2e (closes #144) (#145)

## What & why

**P0 — red `main`.** Fixes #144: `verify-stack` fails on the Playwright e2e step (main runs 2177 after #142, 2190 after #143), while the PR runs passed.

Closes #144

### Root cause

The Maykin **Objecttypen** (S-18a) and **Objecten** (S-18b) images run their `web` under uWSGI with **4 processes × 4 threads by default** (`UWSGI_PROCESSES:-4`). Two web services × 4 idle Django workers (~200 MB each) sat idle during the e2e step and starved the single shared self-hosted runner — Keycloak and the portals stopped responding (the login `#username` never appeared) and Chromium hit `Target crashed`. The runner margin was already thin; the second chain tipped it over (main green through run 2159, red from 2177).

### Fix

Cap `UWSGI_PROCESSES: "1"` + `UWSGI_THREADS: "2"` on both `objecten` and `objecttypen` in both compose files. These APIs only serve single-request smoke checks and are idle during e2e, so 1 worker is plenty — it frees ~1–1.5 GB. The `-init` containers ignore it (they run `setup_configuration`, not uwsgi).

## Verified locally

Brought the objecten chain up with the cap: both services reach healthy, worker count drops from 6 (master + http + 4 workers) to 3 (master + http + 1 worker) per service, and `make verify-objecten` / `make verify-objecttypen` both still → **OK — no-auth 401, token 200**. `docker compose config` clean on both files.

## Definition of Done

- [x] Linked issue (#144).
- [x] Conventional Commit referencing #144.
- [x] Verified locally (both APIs healthy + smoke green with 1 worker).
- [x] Closed by the merging PR (`closes #144`).

No ADR: config-only tuning of existing services — no boundary, dependency, or coupling change.

🤖 Generated with [Claude Code](https://claude.com/claude-code)Reviewed-on: #145

infra/docker-compose.local.yml

@@ -583,6 +583,9 @@ services:
   objecttypen-init:
     image: docker.io/maykinmedia/objecttypes-api:${OBJECTTYPES_TAG:-3.4.2}
     environment: &objecttypen-env-local
+      # 1 uWSGI worker, not the image default of 4×4 (#144) — idle workers starve the CI runner.
+      UWSGI_PROCESSES: "1"
+      UWSGI_THREADS: "2"
       DJANGO_SETTINGS_MODULE: objecttypes.conf.docker
       SECRET_KEY: ${OBJECTTYPES_SECRET_KEY:-dev-only-not-for-production}
       DB_HOST: objecttypen-db
@@ -644,6 +647,9 @@ services:
   objecten-init:
     image: docker.io/maykinmedia/objects-api:${OBJECTS_TAG:-3.4.0}
     environment: &objecten-env-local
+      # 1 uWSGI worker, not the image default of 4×4 (#144) — idle workers starve the CI runner.
+      UWSGI_PROCESSES: "1"
+      UWSGI_THREADS: "2"
       DJANGO_SETTINGS_MODULE: objects.conf.docker
       SECRET_KEY: ${OBJECTS_SECRET_KEY:-dev-only-not-for-production}
       DB_HOST: objecten-db

infra/docker-compose.yml

@@ -596,6 +596,11 @@ services:
   objecttypen-init:
     image: docker.io/maykinmedia/objecttypes-api:${OBJECTTYPES_TAG:-3.4.2}
     environment: &objecttypen-env
+      # 1 uWSGI worker, not the image default of 4×4: this API only serves single-request smoke
+      # checks and sits idle during the e2e step — 4 idle Django workers each pin ~200 MB and starve
+      # the shared CI runner (#144). Init ignores this (it runs setup_configuration, not uwsgi).
+      UWSGI_PROCESSES: "1"
+      UWSGI_THREADS: "2"
       DJANGO_SETTINGS_MODULE: objecttypes.conf.docker
       SECRET_KEY: ${OBJECTTYPES_SECRET_KEY:-dev-only-not-for-production}
       DB_HOST: objecttypen-db
@@ -662,6 +667,9 @@ services:
   objecten-init:
     image: docker.io/maykinmedia/objects-api:${OBJECTS_TAG:-3.4.0}
     environment: &objecten-env
+      # 1 uWSGI worker, not the image default of 4×4 — see the objecttypen note above (#144).
+      UWSGI_PROCESSES: "1"
+      UWSGI_THREADS: "2"
       DJANGO_SETTINGS_MODULE: objects.conf.docker
       SECRET_KEY: ${OBJECTS_SECRET_KEY:-dev-only-not-for-production}
       DB_HOST: objecten-db