chore(build): adapt dev workflow to dual-cluster features

- scripts/build-all.sh now takes a cluster argument (mainnet|devnet) and
  passes it through to cargo build-sbf. The program ID for IDL generation
  is derived from the resulting keypair instead of being passed in.
- tests-sdk/package.json validator:start now builds with --features devnet
  before launching solana-test-validator and reads the program ID via
  solana-keygen pubkey on the keypair file (matching upstream pattern).
- DEVELOPMENT.md updated with the new build invocations, --features devnet
  for cargo test, and a "Mainnet Deploy Strategy" section documenting the
  slot-sharing arrangement with lazorkit-protocol and the binary swap at
  contract end.
- Cargo.lock regenerated for the security-txt deps added in the previous
  commit.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: onspeedhp