feat: merge hybrid clusters into cluster cmd

[Davidonium]

Merge hybrid cluster commands into the cluster command

This PR unifies the hybrid cluster subcommand tree with the main cluster command, eliminating a parallel command hierarchy and giving all clusters (cloud-hosted and hybrid) a single, consistent interface.

What changed

Command structure

• Removed the hybrid cluster subcommand entirely (internal/cmd/hybrid/cluster*.go deleted)
• Moved package subcommands to the root (qcloud package list instead of qcloud cluster package list)
• cluster create, cluster update, cluster describe, and cluster list now handle both cloud-hosted and hybrid clusters transparently

Flag coverage

• cluster create and cluster update now accept the full set of hybrid-specific flags: --service-type, --node-selector, --toleration, --topology-spread-constraint, --annotation, --pod-label, --service-annotation, --reserved-cpu-percentage, storage class flags, TLS flags, audit logging flags, and more
• Flags are shared and defined once; create/update apply the same logic, so parity is guaranteed going forward

Code organization

• Extracted hybrid-specific parse/format helpers into internal/cmd/cluster/hybrid_helpers.go
• Grouped flag declarations by purpose (collection config, performance, service, TLS, audit logging, storage) to make it easy to see what each flag group controls
• undiffableFlags variable identifies flags with complex nested values that can only show (changed) in restart prompts