devtools: Add commitlint to pre-commit.

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 497750a0..2db847f3 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -67,6 +67,12 @@ repos:
       exclude: ccan|contrib|tests/fuzz/corpora
       stages: [ manual ]
 
+- repo: https://github.com/alessandrojcm/commitlint-pre-commit-hook
+  rev: v9.23.0
+  hooks:
+    - id: commitlint
+      stages: [commit-msg]
+
 - repo: local
   hooks:
     # Reimplementation of `make check-amount-access` for pygrep.
diff --git a/commitlint.config.js b/commitlint.config.js
new file mode 100644
index 00000000..f156abd3
--- /dev/null
+++ b/commitlint.config.js
@@ -0,0 +1,56 @@
+module.exports = {
+
+  plugins: [
+    {
+      rules: {
+        'core-lightning': ({ type }) => {
+          // Allow standard Core Lightning types
+          const standardTypes = [
+            // Daemons
+            'channeld', 'closingd', 'connectd', 'gossipd', 'hsmd', 'lightningd', 'onchaind',
+            'openingd',
+            // Related
+            'bitcoin', 'cli', 'cln-grpc', 'cln-rpc', 'db', 'wallet', 'wire',
+            // Others
+            'ci', 'common', 'contrib', 'devtools', 'docs', 'docker', 'github', 'global',
+            'meta', 'nit', 'nix', 'release', 'script', 'tests',
+          ];
+
+          // Extensions
+          const extensions = ['plugin-', 'pyln-', 'tool-']
+          if (type) {
+            for (const prefix of extensions) {
+              if (type.startsWith(prefix)) {
+                return [true];
+              }
+            }
+          }
+
+          // Otherwise, must be a standard type
+          if (standardTypes.includes(type)) {
+            return [true];
+          }
+
+          return [
+            false,
+            `Type must be one of [${standardTypes.join(', ')}] or match patterns [${extensions.join(', ')}]`
+          ];
+        },
+      },
+    },
+  ],
+
+  rules: {
+    // Disable the default type-enum rule since we're using custom validation
+    'type-enum': [0],
+
+    // Enable our custom rule
+    'core-lightning': [2, 'always'],
+
+    // Keep other standard rules
+    'type-case': [2, 'always', 'lower-case'],
+    'type-empty': [2, 'never'],
+    'subject-empty': [2, 'never'],
+    'subject-case': [2, 'never', ['upper-case']],
+  },
+};