refactor!: 9.0.0 cut — drop wire-internal surface, IntoOptionSpec, FpssConnectArgs, public-API discipline (closes #500)

[userFRM]

Summary

Wave 4 of the audit-sweep refactor. ThetaDataDx 9.0.0 cuts the public surface to what users actually need and removes wire-internal state from every binding (Rust, C ABI, Python, TypeScript, C++).

B1 — Drop wire-internal contract_id: i32

Surface	Before	After
Rust	ThetaDataDx::{contract_map, contract_lookup}, FpssClient::{contract_map, contract_lookup}	removed
C ABI	tdx_unified_contract_map, tdx_unified_contract_lookup, tdx_fpss_contract_map, tdx_fpss_contract_lookup, tdx_contract_map_array_free, TdxContractMapArray, TdxContractMapEntry	removed
Python	contract_map(), contract_lookup()	removed
TypeScript	contractMap(), contractLookup()	removed
C++	FpssClient::{contract_map, contract_lookup}	removed

The reader-thread cache stays internal. Consumers that still need an id→contract map build it from the FpssControl::ContractAssigned { id, contract } event stream — every event still carries the assignment.

// Before:
let map = client.contract_map()?;

// After: build the map yourself from the event stream.
client.start_streaming(|event| {
    if let FpssEvent::Control(FpssControl::ContractAssigned { id, contract }) = event {
        my_map.insert(*id, Arc::clone(contract));
    }
})?;

B2 — pub mod proto → pub(crate)

The generated protobuf module is wire-internal. Bindings that need DataTable / DataValueList / ResponseData / Price / data_value::* consume the new thetadatadx::wire re-export, which surfaces only the types offline-decode harnesses actually use.

// Before:
use thetadatadx::proto::{DataTable, ResponseData};

// After:
use thetadatadx::wire::{DataTable, ResponseData};

B3 — pub mod fpss::{connection, framing, dispatcher, ring} → pub(crate)

Only protocol remains a public submodule of fpss. Frame, read_frame, write_frame are surfaced as items at thetadatadx::fpss:: for benchmark consumers; everything else (TLS connect, ring-buffer wait strategies, dispatcher internals) is now crate-private.

// Before:
use thetadatadx::fpss::framing::{read_frame, write_frame, Frame};

// After:
use thetadatadx::fpss::{read_frame, write_frame, Frame};

B4 — FpssConnectArgs replaces 9-arg connect

// Before:
FpssClient::connect(&creds, &hosts, 4096, FpssFlushMode::default(),
                    ReconnectPolicy::default(), true, handler)?;

// After:
let args = FpssConnectArgs::new(&creds, &hosts);
FpssClient::connect(args, handler)?;

Default impl + FpssConnectArgs::new(creds, hosts) shortcut cover the common path.

B5 — Contract::option polymorphic via IntoOptionSpec

// Before:
let c = Contract::option("SPY", "20261218", "60", "C")?;
let c = Contract::option_raw("SPY", 20261218, true, 60_000);

// After:
let c = Contract::option("SPY", ("20261218", "60", "C"))?;
let c = Contract::option("SPY", (20261218, true, 60_000))?;

New sealed trait IntoOptionSpec accepts either (&str, &str, &str) (human-friendly: expiration / strike / right) or (i32, bool, i32) (wire-format integer triple). Contract::option_raw is gone.

Public-API discipline sweep

• auth::{creds, nexus, session} reduced to pub(crate); user-facing types stay re-exported at thetadatadx::auth::* and the crate root.
• Dead helpers removed: fpss::connection::connect_to, fpss::framing::FrameReadState::is_idle, fpss::ring::DEFAULT_RING_SIZE.
• Every pub fn / pub struct reachable from a public path was audited; internal helpers (parsers, decoders, format converters, TLS connect entry points) are now crate-private.

Versions

• thetadatadx 8.0.37 → 9.0.0
• tdbe 0.12.10 → 0.13.0 (eastern-time + json_canon + conditions codegen surface expansion warrants the minor bump)

All seven Cargo.tomls, four npm package.jsons, and five Cargo.lock files updated atomically. python3 scripts/check_version_sync.py reports version sync: ok.

Test plan

• cargo fmt --all -- --check
• cargo clippy --workspace --all-targets -- -D warnings
• cargo test --workspace (every crate green)
• cargo deny check — advisories ok, bans ok, licenses ok, sources ok
• cargo run -p thetadatadx --bin generate_sdk_surfaces --features config-file -- --check
• cargo check --manifest-path tools/cli/Cargo.toml --locked
• cargo check --manifest-path tools/server/Cargo.toml --locked
• python3 scripts/check_version_sync.py
• cmake -S sdks/cpp -B build/cpp && cmake --build build/cpp --target thetadatadx_cpp
• cmake --build build/cpp --target thetadatadx_fpss_smoke

Closes #500.