feat(resolver): replace pubgrub with Composer-ported SAT solver

Add mozart-sat-resolver crate implementing a CDCL SAT-based dependency
resolver ported from Composer's DependencyResolver. This replaces the
pubgrub library to ensure identical resolution behavior with Composer.

The new crate includes: pool (package storage with integer IDs),
rule/rule_set/rule_set_generator (constraint encoding), decisions
(assignment tracking), rule_watch_graph (2-watched literal BCP),
solver (CDCL loop with conflict analysis and clause learning),
policy (version preference), problem (Composer-style error messages),
and transaction (install/update/uninstall operation computation).

The registry resolver is rewritten to use PoolBuilder → RuleSetGenerator
→ Solver pipeline instead of pubgrub's DependencyProvider trait.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/crates/mozart-sat-resolver/src/lib.rs b/crates/mozart-sat-resolver/src/lib.rs
new file mode 100644
index 0000000..2e3fefb
--- /dev/null
+++ b/crates/mozart-sat-resolver/src/lib.rs
@@ -0,0 +1,25 @@
+pub mod decisions;
+pub mod error;
+pub mod policy;
+pub mod pool;
+pub mod pool_builder;
+pub mod problem;
+pub mod request;
+pub mod rule;
+pub mod rule_set;
+pub mod rule_set_generator;
+pub mod rule_watch_graph;
+pub mod solver;
+pub mod transaction;
+
+// Re-export key types for public API
+pub use error::SolverError;
+pub use policy::DefaultPolicy;
+pub use pool::{Literal, PackageId, Pool, PoolLink, PoolPackage, PoolPackageInput};
+pub use pool_builder::{PoolBuilder, make_pool_links};
+pub use request::Request;
+pub use rule::{ReasonData, Rule, RuleReason};
+pub use rule_set::RuleSet;
+pub use rule_set_generator::RuleSetGenerator;
+pub use solver::{Solver, SolverResult};
+pub use transaction::{LockTransaction, Operation, Transaction};