refactor(cli): move sidecar process management from node to CLI

Move paymaster and VRF sidecar process spawning and lifecycle management
from the node module to the CLI layer. The node now treats all paymaster
and VRF services as external (just URLs), while the CLI handles spawning
and managing sidecar processes when running in sidecar mode.

Changes:
- Add crates/cli/src/sidecar.rs with process management code
- Simplify node config to remove ServiceMode enum
- Node exposes bootstrap data via LaunchedNode::sidecar_bootstrap()
- CLI automatically allocates free ports for sidecars
- Properly shutdown sidecar processes on node exit

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: kariy

Cargo.lock

@@ -23,6 +23,7 @@ alloy-primitives.workspace = true
 anyhow.workspace = true
 clap.workspace = true
 console.workspace = true
+reqwest = { workspace = true, optional = true }
 serde.workspace = true
 serde_json.workspace = true
 shellexpand = "3.1.0"
@@ -39,6 +40,7 @@ starknet.workspace = true
 [features]
 paymaster = [
 	"dep:katana-slot-controller",
+	"dep:reqwest",
 	"katana-node/paymaster",
 	"katana-rpc-server/paymaster",
 ]