crates, bindings: correct stated MSRV to 1.85

[ifaouibadi]

Summary

• crates/Cargo.toml [workspace.package] rust-version stated 1.82; a full cargo metadata --locked audit of the resolved graph shows the true maximum declared rust-version in the tree is 1.85 (curve25519-dalek 5.0.0, and the blake2/sha2 0.11 chain: digest, ed25519-dalek, sha2, blake2, zeroize, hybrid-array, ctutils, rand_core 0.10). Corrected to 1.85.
• The two binding trees that path-depend on ae-core and carry their own Cargo.lock — bindings/dart/rust and bindings/python — each independently declared the same stale 1.82 and resolve to the same true maximum 1.85 (verified per-tree with their own cargo metadata --locked, not inherited). Corrected both to match.
• bindings/wasm-js/core-component/Cargo.toml declares no rust-version field at all, so there is no stale value to fix; its resolved graph also tops out at 1.85 if the field is ever added. Left untouched — out of scope for a documentation-correction PR.
• No toolchain change: crates/rust-toolchain.toml and bindings/wasm-js/core-component/rust-toolchain.toml stay pinned at 1.97.1, already above the corrected floor.

Test plan

• cargo check --locked --workspace in crates/ — clean, no lockfile drift
• cargo check --locked in bindings/dart/rust — clean, no lockfile drift
• cargo check --locked in bindings/python — clean, no lockfile drift
• git status confirms only the three Cargo.toml files changed; no Cargo.lock touched anywhere

[github-actions]

Thanks for the pull request — it is in the queue and a maintainer will review it.

This repository is maintained on a weekly cadence. Anything opened from outside gets
a human reply within 2 business days; this comment is automation confirming your
pull request landed, and it is not that reply.

What happens next:

• CI runs on the pull request. Check, Build and Test need to be green before
  review — you can push fixes straight to the same branch.
• A maintainer reviews it against CONTRIBUTING.md.
• A change to a package's public API, or a new dependency, needs a maintainer
  decision before it can merge. That is where the call gets made rather than a
  delay, and we will tell you either way instead of leaving it open.

If this is a security fix for an unreported vulnerability, please close it and use
the private channel first — SECURITY.md.
A public pull request describes the flaw to everyone before the fix is released.