ci: add PR size and title checks, configure commitizen

Add two new GitHub Actions workflows:
- pr-size.yml: auto-labels PRs by size and fails CI on PRs over 500 lines
- pr-title.yml: enforces conventional commit format on PR titles

Configure commitizen in pyproject.toml with strict schema pattern matching
for conventional commits.

.github/workflows/pr-size.yml

@@ -0,0 +1,37 @@
+name: PR Size Check
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened]
+
+jobs:
+  pr-size:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - uses: codelytv/pr-size-labeler@v1
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          xs_label: "size/XS"
+          xs_max_size: 25
+          s_label: "size/S"
+          s_max_size: 100
+          m_label: "size/M"
+          m_max_size: 250
+          l_label: "size/L"
+          l_max_size: 500
+          xl_label: "size/XL"
+          fail_if_xl: true
+          message_if_xl: >
+            This PR exceeds 500 lines changed and has been labeled `size/XL`.
+            PRs of this size require release manager approval to merge.
+            Please consider splitting into smaller PRs, or add a justification
+            in the PR description for why this cannot be broken up.
+          files_to_ignore: |
+            uv.lock
+            *.lock
+            lib/crewai/src/crewai/cli/templates/**
+            **/*.json
+            **/test_durations/**
+            **/cassettes/**

.github/workflows/pr-title.yml

@@ -0,0 +1,38 @@
+name: PR Title Check
+
+on:
+  pull_request:
+    types: [opened, edited, synchronize, reopened]
+
+jobs:
+  pr-title:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: amannn/action-semantic-pull-request@v5
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          types: |
+            feat
+            fix
+            refactor
+            perf
+            test
+            docs
+            chore
+            ci
+            style
+            revert
+          requireScope: false
+          subjectPattern: ^[a-z].+[^.]$
+          subjectPatternError: >
+            The PR title "{title}" does not follow conventional commit format.
+
+            Expected: <type>(<scope>): <lowercase description without trailing period>
+
+            Examples:
+              feat(memory): add lancedb storage backend
+              fix(agents): resolve deadlock in concurrent execution
+              chore(deps): bump pydantic to 2.11.9
+
+            See RELEASE_PROCESS.md for the full commit message convention.

pyproject.toml

@@ -142,6 +142,22 @@ python_files = "test_*.py"
 python_classes = "Test*"
 python_functions = "test_*"
 
+[tool.commitizen]
+name = "cz_conventional_commits"
+version_provider = "scm"
+tag_format = "$version"
+allowed_prefixes = ["Merge", "Revert"]
+changelog_incremental = true
+update_changelog_on_bump = false
+
+[tool.commitizen.customize]
+schema = "<type>(<scope>): <description>"
+schema_pattern = "^(feat|fix|refactor|perf|test|docs|chore|ci|style|revert)(\\(.+\\))?!?: .{1,72}"
+bump_pattern = "^(feat|fix|perf|refactor|revert)"
+bump_map = { feat = "MINOR", fix = "PATCH", perf = "PATCH", refactor = "PATCH", revert = "PATCH" }
+info = "Commits must follow Conventional Commits 1.0.0. See RELEASE_PROCESS.md for details."
+
+
 [tool.uv]
 
 # composio-core pins rich<14 but textual requires rich>=14.