chore(#1): Use timestamp-based dev versions to match JS client

Switch dev version suffix from pipeline number to UTC timestamp
(YYYYMMDDHHmmss) for cross-SDK consistency:
  Python: 0.1.0.dev20260215045901  (PEP 440)
  JS:     0.1.0-dev.20260215045901 (semver)

Refs #1

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.woodpecker.yml

@@ -65,7 +65,6 @@ steps:
         from_secret: gitea_token
       CI_COMMIT_BRANCH: ${CI_COMMIT_BRANCH}
       CI_COMMIT_TAG: ${CI_COMMIT_TAG}
-      CI_PIPELINE_NUMBER: ${CI_PIPELINE_NUMBER}
     commands:
       - |
         uv sync --all-extras --frozen
@@ -76,7 +75,8 @@ steps:
           VERSION="$$BASE_VERSION"
           echo "Release build: $$VERSION"
         elif [ "$$CI_COMMIT_BRANCH" = "develop" ]; then
-          VERSION="$${BASE_VERSION}.dev$${CI_PIPELINE_NUMBER}"
+          TIMESTAMP=$$(date -u +%Y%m%d%H%M%S)
+          VERSION="$${BASE_VERSION}.dev$${TIMESTAMP}"
           echo "Dev build: $$VERSION"
           sed -i "s/version = \"$$BASE_VERSION\"/version = \"$$VERSION\"/" pyproject.toml
         fi