feat(http): add bounded HTTP and callable SSE clients

[fffonion]

Summary

• add bounded buffered HTTP requests and callable-driven SSE streams
• use the generic one-item host stream pump with explicit delivery, completion, stop, failure, and rollback semantics
• enforce DNS and redirect revalidation, credential stripping, response budgets, absolute deadlines, cancellation, and exactly-once cleanup
• target-gate the native transport while preserving runtime, no-std, and WASM compatibility boundaries

Stack

• Base: feat(compiler): add resource typing, ownership, VMBC and LSP integration #24
• Top of stack
• Commit: 4b74986

Validation

• HTTP host: 23 tests
• HTTP/SSE: 21 tests
• IO/HTTP coexistence: 11 tests
• SSE deadline scheduling case: 10 repeated passes
• cargo test --workspace --all-targets --all-features
• strict workspace Clippy
• no-default/runtime/no-std/WASM checks
• workspace release all-features build
• architecture boundary tests