feat(hanzoai): regenerate client from unified OpenAPI spec (retire Stainless) (#45)

Replace the Stainless-generated `hanzoai` client (188 legacy LLM-gateway
endpoints) with an openapi-generator `python` (urllib3 + pydantic v2)
client built from hanzoai/openapi `hanzo.yaml` — the full unified
api.hanzo.ai/v1 surface (493 API groups, 1710 models, all /v1 products).

- scripts/generate.sh: the one-way generator; emits only pkg/hanzoai
  (other pkg/hanzo-* packages untouched).
- pyproject: deps -> urllib3 / python-dateutil / pydantic>=2 /
  typing-extensions; version 2.2.3 -> 3.0.0 (breaking surface change).
- tests/: Stainless client tests replaced with a surface smoke test.
- .github/workflows/generate.yml: regenerate on openapi spec-update.
- Base URL https://api.hanzo.ai, Bearer hk- / JWT auth.

Verified: wheel hanzoai-3.0.0 builds, installs into a clean venv, and
`import hanzoai` + product API construction succeed.

Co-authored-by: Hanzo Dev <[email protected]>

scripts/generate.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+# Regenerate the Hanzo Python client (`hanzoai`) from the unified OpenAPI spec.
+#
+# The ONE way: hanzoai/openapi `hanzo.yaml` is the single source of truth. The
+# `hanzoai` package under pkg/ is generated from it with openapi-generator — no
+# Stainless. Other pkg/hanzo-* packages are hand-written and untouched here.
+#
+#   ./scripts/generate.sh                 # pulls spec from hanzoai/openapi@main
+#   SPEC=/path/to/hanzo.yaml ./scripts/generate.sh   # local spec override
+#
+# Requires: java 17+, curl.
+set -euo pipefail
+cd "$(dirname "$0")/.."
+
+GENERATOR_VERSION="${GENERATOR_VERSION:-7.14.0}"
+SPEC_URL="${SPEC_URL:-https://raw.githubusercontent.com/hanzoai/openapi/main/hanzo.yaml}"
+SPEC="${SPEC:-}"
+JAR="${JAR:-/tmp/openapi-generator-cli-${GENERATOR_VERSION}.jar}"
+
+if [ -z "$SPEC" ]; then
+  SPEC="$(mktemp)"; curl -fsSL "$SPEC_URL" -o "$SPEC"
+fi
+if [ ! -f "$JAR" ]; then
+  curl -fsSL -o "$JAR" \
+    "https://repo1.maven.org/maven2/org/openapitools/openapi-generator-cli/${GENERATOR_VERSION}/openapi-generator-cli-${GENERATOR_VERSION}.jar"
+fi
+
+OUT="$(mktemp -d)"
+java -jar "$JAR" generate \
+  -i "$SPEC" -g python \
+  --additional-properties=packageName=hanzoai,projectName=hanzoai,library=urllib3 \
+  --global-property=apiTests=false,modelTests=false,apiDocs=false,modelDocs=false \
+  --git-user-id=hanzoai --git-repo-id=python-sdk \
+  -o "$OUT"
+
+# Only the package itself lives in this monorepo (pkg/hanzoai). The generated
+# pyproject/setup/README/etc. are discarded — the repo root owns build config.
+rm -rf pkg/hanzoai
+cp -r "$OUT/hanzoai" pkg/hanzoai
+echo "generated $(find pkg/hanzoai -name '*.py' | wc -l) python files into pkg/hanzoai"