fix: patch Rustls advisories across all Maple components

[AnthonyRonning]

The October 15 nightly supply-chain checks began failing on rustls 0.23.45 because of RUSTSEC-2026-0346, RUSTSEC-2026-0347, RUSTSEC-2026-0348 and RUSTSEC-2026-0349. Update the locked dependency to the patched 0.23.46.

Only the rustls version and checksum change; manifests, other dependencies, features and advisory exceptions are unchanged.

Validation:

• Cargo resolved the targeted update offline; parsed before/after lockfiles confirm no other graph changes.
• Local cargo-deny 0.19.6: --all-features --locked check advisories bans passed, using a refreshed RustSec database.
• git diff --check passed.
• Full component builds/tests were not run locally: preparing the pinned Nix environments failed with no space left on device. Hosted CI remains required.

Covers all five Maple Rust lockfiles: Research/Tauri, OpenSecret backend, Rust SDK, standalone proxy and Maple Agent. Agent also passed the advisory/bans check using the existing Research deny policy, with one unused-ignore warning.

Local resolution/audit used already installed Nix Cargo/Rust 1.95.0 after the component shells failed; component build/test hooks were skipped because of that disk limit. No local application, service, platform-package or production validation is claimed.

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