Add Canton stack support to the installer

[fernandomg]

Problem statement

The installer only scaffolds the EVM stack. We want it to also scaffold the Canton stack (Daml ledger, Carpincho wallet, off-chain services) through the same interactive and non-interactive flows.

Proposed solution

• Generalize the installer into a config-driven stack abstraction; add the Canton stack (--canton/--evm/--stack).
• Canton features (counter, e2e, carpincho, llm), all default-on, with data-driven cleanup; e2e requires counter (auto-resolved).
• Repo hygiene: always strip CI + husky/commitlint; Canton keeps agent docs under the llm feature.
• Gather all interactive answers before any disk work (+ confirmation step) and remove a partial scaffold on Ctrl+C.

Acceptance criteria

• --canton / --evm / --stack select the stack; --info lists each stack's features and dependencies.
• Full and custom installs work for both stacks (live-verified against BootNodeDev/cn-dappbooster).
• Interrupting an install leaves no partial directory behind.
• build + lint + tests green.