Fixed: enforce per-insertion validation for PLManifoldStrict topology

Correct the validation policy during batch construction so that
topologies requiring vertex links maintain Always validation. This
ensures structural guarantees are preserved during bulk operations.
Additionally updates MSRV to 1.94, refreshes dependencies, and
expands contributor guidelines in AGENTS.md.

Refs: issue-228

Author: acgetchell

AGENTS.md

@@ -45,9 +45,16 @@ When user requests commit message generation:
 - Prefer borrowed APIs by default:
   take references (`&T`, `&mut T`, `&[T]`) as arguments and return borrowed views (`&T`, `&[T]`) when possible.
   Only take ownership or return `Vec`/allocated data when required.
+- **Error handling**:
+  - All public functions must return `Result` types
+  - Private functions should return `Result` if called from public functions to surface errors properly
+  - As a scientific library, panics are rarely acceptable - prefer explicit error propagation
+  - Define error types at the top of the relevant module/file (module-local errors, not centralized)
+- **Preludes**: Keep minimal and orthogonal by function. Users should be able to import well-named preludes to accomplish
+  specific goals without bringing in unrelated items.
 - Integration tests in `tests/*.rs` are separate crates; add a crate-level doc comment (`//! ...`) at the top to satisfy clippy `missing_docs` (CI uses `-D warnings`).
 - **Module layout**: Never use `mod.rs`.
-  Declare modules in `src/lib.rs` (and `src/main.rs` for binaries), including nested modules via inline `pub mod foo { pub mod bar; }` when needed.
+  Declare modules in `src/lib.rs`, including nested modules via inline `pub mod foo { pub mod bar; }` when needed.
 
 ### Python
 
@@ -59,21 +66,27 @@ When user requests commit message generation:
 ## Common Commands
 
 ```bash
-just fix              # Apply formatters/auto-fixes (mutating)
+just fix              # Apply formatters/auto-fixes (mutating) - most formatters run automatically
 just check            # Lint/validators (non-mutating)
 just ci               # Full CI run (checks + all tests + examples + bench compile)
-just ci-slow          # CI + slow tests (100+ vertices)
+just ci-slow          # CI + slow tests (100+ vertices) - long-running
 just lint             # All linting
 just test             # Lib and doc tests
 just test-integration # Integration tests (includes proptests)
 just test-all         # All tests (Rust + Python)
 just examples         # Run all examples
+just changelog        # Regenerate CHANGELOG.md from git commits
 ```
 
+## Testing Guidance
+
+- **Property tests**: Integration tests include proptests; failures show seed for reproduction
+- **Documentation**: After Rust changes, run `just doc-check` to verify docs build
+- **Validation order**: Run formatters (`just fix`) before tests to avoid formatting noise in diffs
+
 ### Changelog
 
-- Never edit `CHANGELOG.md` directly - it's auto-generated from git commits
-- Use `just changelog` to regenerate
+- Never edit `CHANGELOG.md` directly - it's auto-generated from git commits via `just changelog`
 
 ### GitHub Issues
 
@@ -95,7 +108,7 @@ When creating or updating issues:
 
 ## Project Context
 
-- **Rust** d-dimensional Delaunay triangulation library (MSRV 1.93.1, Edition 2024)
+- **Rust** d-dimensional Delaunay triangulation library (MSRV 1.94, Edition 2024)
 - **No unsafe code**: `#![forbid(unsafe_code)]`
 - **Architecture**: Generic with `const D: usize` for dimension (tested 2D-5D)
 - **Modules**: `src/core/` (data structures), `src/geometry/` (predicates)

Cargo.lock

@@ -2,7 +2,7 @@
 name = "delaunay"
 version = "0.7.1"
 edition = "2024"
-rust-version = "1.93.1"
+rust-version = "1.94"
 authors = [ "Adam Getchell <adam@adamgetchell.org>" ]
 homepage = "https://github.com/acgetchell/delaunay"
 documentation = "https://docs.rs/delaunay"
@@ -19,7 +19,7 @@ readme = "README.md"
 allocation-counter = { version = "0.8.1", optional = true } # for memory profiling
 arc-swap = "1.8.2"
 derive_builder = "0.20.2"
-la-stack = "0.1.3"
+la-stack = "0.2.0"
 tracing = "0.1.44"
 rustc-hash = "2.1.1" # Fast non-cryptographic hashing for performance
 smallvec = { version = "1.15.1", features = [ "serde" ] } # Stack allocation for small collections
@@ -29,7 +29,7 @@ rand = "0.10.0"
 serde = { version = "1.0.228", features = [ "derive" ] }
 slotmap = { version = "1.1.1", features = [ "serde" ] }
 thiserror = "2.0.18"
-uuid = { version = "1.21.0", features = [ "v4", "serde", "fast-rng" ] }
+uuid = { version = "1.22.0", features = [ "v4", "serde", "fast-rng" ] }
 
 [dev-dependencies]
 approx = "0.5.1"

Cargo.toml

@@ -2,7 +2,7 @@
 # This ensures consistent configuration across all developers and IDEs
 
 # Minimum Supported Rust Version - matches Cargo.toml and rust-toolchain.toml
-msrv = "1.93.1"
+msrv = "1.94"
 
 # Note: Lint levels are controlled via command-line flags in AGENTS.md:
 # cargo clippy --workspace --all-targets --all-features -- -D warnings -W clippy::pedantic -W clippy::nursery -W clippy::cargo

clippy.toml

@@ -56,6 +56,10 @@ macro_rules! generate_memory_analysis {
             clippy::too_many_lines,
             reason = "Example keeps analysis flow in one function for readability"
         )]
+        #[expect(
+            clippy::result_large_err,
+            reason = "ConvexHullConstructionError contains TdsValidationError which is large; performance impact is negligible in this example"
+        )]
         fn $name(point_counts: &[usize], seeds: &[u64]) {
             let mut any_success = false;
             for &n_points in point_counts {

examples/memory_analysis.rs

@@ -1,6 +1,6 @@
 [toolchain]
 # Pin to MSRV as specified in Cargo.toml
-channel = "1.93.1"
+channel = "1.94"
 
 # Essential components for development
 components = [

rust-toolchain.toml

@@ -2745,13 +2745,17 @@ where
         // potential issue (e.g. after rollback/retry).  A comprehensive post-
         // construction validation in finalize_bulk_construction catches any issues
         // that slip through.
+        //
+        // Exception: PLManifoldStrict requires per-insertion vertex-link validation,
+        // so we must use ValidationPolicy::Always to satisfy that guarantee.
         let original_validation_policy = dt.tri.validation_policy;
         dt.tri.validation_policy = if dt
             .tri
             .topology_guarantee
             .requires_vertex_links_during_insertion()
-            || dt.tri.topology_guarantee.requires_ridge_links()
         {
+            ValidationPolicy::Always
+        } else if dt.tri.topology_guarantee.requires_ridge_links() {
             ValidationPolicy::OnSuspicion
         } else {
             ValidationPolicy::DebugOnly
@@ -2850,13 +2854,17 @@ where
         // During batch construction, use suspicion-driven validation instead of
         // per-insertion validation (see _with_construction_statistics variant for
         // rationale: O(n²) avoidance + post-construction catch-all).
+        //
+        // Exception: PLManifoldStrict requires per-insertion vertex-link validation,
+        // so we must use ValidationPolicy::Always to satisfy that guarantee.
         let original_validation_policy = dt.tri.validation_policy;
         dt.tri.validation_policy = if dt
             .tri
             .topology_guarantee
             .requires_vertex_links_during_insertion()
-            || dt.tri.topology_guarantee.requires_ridge_links()
         {
+            ValidationPolicy::Always
+        } else if dt.tri.topology_guarantee.requires_ridge_links() {
             ValidationPolicy::OnSuspicion
         } else {
             ValidationPolicy::DebugOnly