toolchain: Rust 1.98.1 -> 1.99.0 (+ lance 13 / lancedb 0.40 where pinned)

Non-comment pins only (rust-toolchain.toml, rust-version, CI MSRV, Dockerfile
images); historical comments untouched. lance/lancedb moved in lockstep with
lance-graph (arrow 58 / datafusion 54 unchanged); lancedb 0.40.0 still needs
`remote` to compile. Verification results follow in the PR.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017YPZhKpSxN7eSxk7VH2vzB

Author: claude

native/lgj-abi/Cargo.toml

@@ -2,7 +2,7 @@
 name = "lgj-abi"
 version = "0.1.0"
 edition = "2021"
-rust-version = "1.98.1"
+rust-version = "1.99.0"
 license = "MIT OR Apache-2.0"
 publish = false
 description = "The lance-graph-java machine membrane: a self-describing, versioned, bulk-only psABI surface. No C, no JNI, no headers."

native/lgj-abi/rust-toolchain.toml

@@ -2,7 +2,7 @@
 # Stable only. Matches ndarray / lance-graph / the rest of the AdaWorldAPI
 # stack. No nightly features anywhere in this crate — in particular no
 # `core::simd` / portable-simd (abi.md §8).
-channel = "1.98.1"
+channel = "1.99.0"
 components = ["clippy", "rustfmt"]
 
 # Bump log (append one line per bump; the version itself is the `channel`