refactor(ci): consolidate per-platform crow workflows into 3 matrix files (#92)

## Summary

Collapse **44** per-platform crow pipeline files into **3** matrix-driven files (one per family), using `matrix.include` + the crow #1165 declarative manual `variables:` block:

| Family | Before | After |
|---|---|---|
| process-updates | 14 | `process-updates.yaml` |
| weekly-audit-missing | 16 | `weekly-audit-missing.yaml` |
| weekly-rebuild-missing | 14 | `weekly-rebuild-missing.yaml` |

- **One file per family** (not split by arch). Arch placement is via the agent label as a matrix var (`artemis`=amd64, `gaia`=arm64) for process-updates and weekly-rebuild; weekly-audit keeps its arch-`nodeSelector` placement (no agent label).
- **Matrix axis is named `OS`** (e.g. `redhat-9`) per request, with per-row `R_VERSION`, image tag, codename, and `process_new` (FALSE for alpine).
- **Runs preserved 1:1:**
  - *Cron*: each existing `<family>-<os>-<arch>` cron still fires only its matching matrix row via `CI_PIPELINE_CRON`. Server-side cron entries unchanged.
  - *Manual*: a #1165 dropdown variable (`process_cran_updates` / `weekly_audit_missing` / `weekly_rebuild_missing`) selects a single `<os>-<arch>` or `all`. weekly-rebuild defaults to `all`, matching its former bare `event: manual` trigger.

## Behavior deltas (intentional, flagged)

To fit one file per family the backend was unified:
- The amd64-only `node.kubernetes.io/instance-type: AX42` nodeSelector pin is **dropped**; placement now relies on the `artemis`/`gaia` agents.
- **process-updates arm64** jobs now share the same `backend_options` as amd64 (resource requests/limits + tolerations) — they previously had none, so they gain an 18Gi memory limit. Tell me if arm64 should stay uncapped.

## Validation required before merge

Relies on crow interpolating matrix variables inside `when.evaluate`, `labels.agent`, and `commands`. Interpolation in image/env/commands is standard crow; the novel bit is `when.evaluate`. The manual dropdown routing exercises the same interpolation as the cron routing, so on this branch:
1. Trigger manually with the dropdown = `redhat-9-amd64` -> confirm only that one job runs (image `build-env-redhat:9`, R 4.4.3, agent artemis).
2. Trigger with `all` -> confirm all os/arch jobs schedule.

Crons only fire on the default branch, so no collision while unmerged. Fallback if `${...}` doesn't interpolate in `when`: a runtime `case "$CI_PIPELINE_CRON" in ...` guard, same files otherwise.

Reviewed-on: #92

.crow/weekly-audit-missing.yaml

@@ -0,0 +1,161 @@
+# Consolidated weekly-audit-missing pipeline (all platforms, both arches).
+# One matrix row per OS/arch replaces the former per-platform files.
+# Routing is preserved 1:1:
+#   - cron:   each existing `weekly-audit-missing-<os>-<arch>` cron fires only
+#             its matching matrix row (via CI_PIPELINE_CRON).
+#   - manual: pick a target from the `weekly_audit_missing` dropdown
+#             ("all" = every os/arch).
+# Arch placement is via the agent label (artemis=amd64, gaia=arm64).
+variables:
+  weekly_audit_missing:
+    description: "Manual run target: a specific <os>-<arch>, or 'all' for every os/arch."
+    options:
+      - all
+      - alpine-321-amd64
+      - alpine-321-arm64
+      - alpine-322-amd64
+      - alpine-322-arm64
+      - alpine-323-amd64
+      - alpine-323-arm64
+      - redhat-8-amd64
+      - redhat-8-arm64
+      - redhat-9-amd64
+      - redhat-9-arm64
+      - redhat-10-amd64
+      - redhat-10-arm64
+      - ubuntu-2204-amd64
+      - ubuntu-2204-arm64
+      - ubuntu-2404-amd64
+      - ubuntu-2404-arm64
+    default: all
+
+when:
+  - event: cron
+    evaluate: 'CI_PIPELINE_CRON == "weekly-audit-missing-${OS}-${ARCH}"'
+  - event: manual
+    evaluate: 'weekly_audit_missing == "all" || weekly_audit_missing == "${OS}-${ARCH}"'
+
+skip_clone: true
+
+labels:
+  agent: ${AGENT}
+
+matrix:
+  include:
+    - OS: alpine-321
+      ARCH: amd64
+      AGENT: artemis
+      R_VERSION: 4.5.3
+      IMG: alpine:3.24
+    - OS: alpine-321
+      ARCH: arm64
+      AGENT: gaia
+      R_VERSION: 4.5.3
+      IMG: alpine:3.24
+    - OS: alpine-322
+      ARCH: amd64
+      AGENT: artemis
+      R_VERSION: 4.5.3
+      IMG: alpine:3.24
+    - OS: alpine-322
+      ARCH: arm64
+      AGENT: gaia
+      R_VERSION: 4.5.3
+      IMG: alpine:3.24
+    - OS: alpine-323
+      ARCH: amd64
+      AGENT: artemis
+      R_VERSION: 4.5.3
+      IMG: alpine:3.24
+    - OS: alpine-323
+      ARCH: arm64
+      AGENT: gaia
+      R_VERSION: 4.5.3
+      IMG: alpine:3.24
+    - OS: redhat-8
+      ARCH: amd64
+      AGENT: artemis
+      R_VERSION: 4.4.3
+      IMG: redhat:8
+    - OS: redhat-8
+      ARCH: arm64
+      AGENT: gaia
+      R_VERSION: 4.4.3
+      IMG: redhat:8
+    - OS: redhat-9
+      ARCH: amd64
+      AGENT: artemis
+      R_VERSION: 4.4.3
+      IMG: redhat:9
+    - OS: redhat-9
+      ARCH: arm64
+      AGENT: gaia
+      R_VERSION: 4.4.3
+      IMG: redhat:9
+    - OS: redhat-10
+      ARCH: amd64
+      AGENT: artemis
+      R_VERSION: 4.5.3
+      IMG: redhat:10
+    - OS: redhat-10
+      ARCH: arm64
+      AGENT: gaia
+      R_VERSION: 4.5.3
+      IMG: redhat:10
+    - OS: ubuntu-2204
+      ARCH: amd64
+      AGENT: artemis
+      R_VERSION: 4.4.3
+      IMG: ubuntu:jammy
+    - OS: ubuntu-2204
+      ARCH: arm64
+      AGENT: gaia
+      R_VERSION: 4.4.3
+      IMG: ubuntu:jammy
+    - OS: ubuntu-2404
+      ARCH: amd64
+      AGENT: artemis
+      R_VERSION: 4.4.3
+      IMG: ubuntu:noble
+    - OS: ubuntu-2404
+      ARCH: arm64
+      AGENT: gaia
+      R_VERSION: 4.4.3
+      IMG: ubuntu:noble
+
+steps:
+  - name: 'Audit missing binaries'
+    image: reg.devxy.io/rpkgs/build-env-${IMG}
+    pull: true
+    environment:
+      B2_S3_ACCESS_KEY:
+        from_secret: B2_S3_ACCESS_KEY
+      B2_S3_SECRET_KEY:
+        from_secret: B2_S3_SECRET_KEY
+      PGPASS:
+        from_secret: PGPASS
+      REPO_RO_TOKEN:
+        from_secret: REPO_RO_TOKEN
+      GITHUB_PAT:
+        from_secret: GITHUB_PAT
+      FORGEJO_TOKEN:
+        from_secret: FORGEJO_TOKEN
+      PLATFORM: ${OS}
+      ARCH: ${ARCH}
+      R_LIBS_USER: /mnt/cache/R-pkgs
+      R_VERSION: ${R_VERSION}
+    commands:
+      - git clone -q https://pat-s:$$REPO_RO_TOKEN@git.devxy.io/devxy/build-cran-binaries.git .
+      - mkdir -p /mnt/cache/packages /mnt/cache/R-pkgs
+      - rm -rf /mnt/cache/R-pkgs/00LOCK-*
+      - /opt/R/$R_VERSION/bin/R -q -e 'pak::pak(c("git::https://codefloe.com/rpkgs/bincraft.git", "httr2", "jsonlite"))'
+      - /opt/R/$R_VERSION/bin/R -q -e 'source("local/weekly-missing-binaries-audit.R")'
+    backend_options:
+      docker:
+        resources:
+          requests:
+            memory: 2Gi
+            cpu: 2000m
+          limits:
+            memory: 4Gi
+            cpu: 2000m