Adds a shared HanzoCloud client (core/cloud.py; lazy httpx, api.hanzo.ai /v1)
and wires the cloud half of the hybrid tools: code gains cross-repo
search/context/ask/index over the cloud index, vector gains a cloud-backed
store plus an infinity-embedded local option, net gains a vision tool. Bumps
hanzo-tools 0.3.2->0.3.3, -code 0.1.2->0.1.3, -net 0.1.2->0.1.3, -vector
0.2.0->0.2.1 and declares httpx where the cloud path is used. New tests cover
the code/net cloud actions. import hanzo_tools.core is green.