ci(codeql): cron weekly→monthly (cut 3, standards#233 Option B) (#41)

## Summary

Single-line cron change in `.github/workflows/codeql.yml` (and any
vendored subpath copies in this repo):

```diff
 schedule:
-  - cron: '0 6 * * 1'   # weekly Monday 06:00 UTC
+  - cron: '0 6 1 * *'   # monthly 1st 06:00 UTC
```

Mirrors `hyperpolymath/standards#286` (canonical caller template).

## Scope

Owner-decision Option B from `standards#233` selected 2026-05-30.
PR-trigger runs (`push` + `pull_request`) unchanged — every PR still
gets CodeQL coverage.

## Sweep

Estate-wide tracker: `hyperpolymath/standards#288`.

Refs hyperpolymath/standards#233 #288 #286

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

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

asdf-augmenters/asdf-control-tower/.github/workflows/codeql.yml

@@ -6,7 +6,7 @@ on:
   pull_request:
     branches: [main]
   schedule:
-    - cron: "0 6 * * 1"
+    - cron: "0 6 1 * *"
 permissions: read-all
 jobs:
   analyze:

asdf-augmenters/asdf-plugin-collection/plugins/casket-ssg/.github/workflows/codeql.yml

@@ -6,7 +6,7 @@ on:
   pull_request:
     branches: [main]
   schedule:
-    - cron: "0 6 * * 1"
+    - cron: "0 6 1 * *"
 permissions: read-all
 jobs:
   analyze:

asdf-augmenters/asdf-plugin-collection/plugins/doctl/.github/workflows/codeql.yml

@@ -7,7 +7,7 @@ on:
   pull_request:
     branches: [main, master]
   schedule:
-    - cron: '0 6 * * 1'
+    - cron: '0 6 1 * *'
 
 permissions: read-all
 

asdf-augmenters/asdf-plugin-collection/plugins/hashicorp/.github/workflows/codeql.yml

@@ -6,7 +6,7 @@ on:
   pull_request:
     branches: [main]
   schedule:
-    - cron: "0 6 * * 1"
+    - cron: "0 6 1 * *"
 permissions: read-all
 jobs:
   analyze:

asdf-augmenters/asdf-plugin-collection/plugins/orchid/.github/workflows/codeql.yml

@@ -7,7 +7,7 @@ on:
   pull_request:
     branches: [main, master]
   schedule:
-    - cron: '0 6 * * 1'
+    - cron: '0 6 1 * *'
 
 permissions: read-all
 

asdf-casket-ssg-plugin/.github/workflows/codeql.yml

@@ -6,7 +6,7 @@ on:
   pull_request:
     branches: [main]
   schedule:
-    - cron: "0 6 * * 1"
+    - cron: "0 6 1 * *"
 permissions: read-all
 jobs:
   analyze:

asdf-control-tower/.github/workflows/codeql.yml

@@ -6,7 +6,7 @@ on:
   pull_request:
     branches: [main]
   schedule:
-    - cron: "0 6 * * 1"
+    - cron: "0 6 1 * *"
 permissions: read-all
 jobs:
   analyze:

asdf-gitleaks-plugin/.github/workflows/codeql.yml

@@ -7,7 +7,7 @@ on:
   pull_request:
     branches: [main, master]
   schedule:
-    - cron: '0 6 * * 1'
+    - cron: '0 6 1 * *'
 
 permissions: read-all
 

asdf-plugin-collection/plugins/casket-ssg/.github/workflows/codeql.yml

@@ -6,7 +6,7 @@ on:
   pull_request:
     branches: [main]
   schedule:
-    - cron: "0 6 * * 1"
+    - cron: "0 6 1 * *"
 permissions: read-all
 jobs:
   analyze:

asdf-plugin-collection/plugins/dhall/.github/workflows/codeql.yml

@@ -7,7 +7,7 @@ on:
   pull_request:
     branches: [main, master]
   schedule:
-    - cron: '0 6 * * 1'
+    - cron: '0 6 1 * *'
 
 permissions: read-all