Add theorem prover docs page with Phase 2 constraint solving

- prove.sx Phase 2: bounded model checking with 34 algebraic properties
  (commutativity, associativity, distributivity, inverses, bounds, transitivity)
- prove.sx generates SMT-LIB for unbounded Z3 verification via z3-expr
- New docs page /plans/theorem-prover with live results (91/91 sat, 34/34 verified)
- Page helper runs both proof phases and returns structured data
- Parser: re-add ' quote syntax (removed by prior edit)
- Load prove.sx alongside z3.sx at startup

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

sx/sx/nav-data.sx

@@ -157,6 +157,8 @@
         :summary "Extensible parse-time transformations via # dispatch — datum comments, raw strings, and quote shorthand.")
   (dict :label "Reader Macro Demo" :href "/plans/reader-macro-demo"
         :summary "Live demo: #z3 translates SX spec declarations to SMT-LIB verification conditions.")
+  (dict :label "Theorem Prover" :href "/plans/theorem-prover"
+        :summary "prove.sx — constraint solver and property prover for SX primitives, written in SX.")
   (dict :label "SX-Activity" :href "/plans/sx-activity"
         :summary "A new web built on SX — executable content, shared components, parsers, and logic on IPFS, provenance on Bitcoin, all running within your own security context.")
   (dict :label "Predictive Prefetching" :href "/plans/predictive-prefetch"