v3.5.1: POMDP belief-state + value-of-information planner + grounded anti-hallucination

Partial observability is now first-class:

- belief.rs — property-graph world model; nodes (host/service/vuln/exploit/cred)
  carry a probability, not a boolean. Bayesian observation updates; per-node
  Shannon entropy; mean-uncertainty + recon-frontier. Black-box = diffuse priors
  that sharpen with observation; white-box collapses toward deterministic (MDP).
- pomdp.rs — value_of_information(), decide() (recon vs exploit falls out of
  belief entropy), and may_assert() — the mathematical anti-hallucination gate:
  no exploitability claim while the belief is diffuse (high entropy) → observe first.
- grounding.rs — verification engine, hard rule "no claim without a tool receipt":
  empirical grounding for black-box (raw HTTP/OOB/error markers), symbolic for
  white-box (file:line into reviewed source). Ungrounded claims demoted + flagged
  receipt_missing (feeds future reward shaping).
- pipeline.finish(): grounding gate before reporting + belief-uncertainty readout.
- bump 3.5.0 → 3.5.1; README documents the v3.5.1 belief/grounding architecture
  and the infra/bandit/reward roadmap.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

neurosploit-rs/Cargo.lock

@@ -695,7 +695,7 @@ dependencies = [
 
 [[package]]
 name = "neurosploit"
-version = "3.5.0"
+version = "3.5.1"
 dependencies = [
  "anyhow",
  "clap",
@@ -710,7 +710,7 @@ dependencies = [
 
 [[package]]
 name = "neurosploit-harness"
-version = "3.5.0"
+version = "3.5.1"
 dependencies = [
  "anyhow",
  "futures",