Add Maritime/Logistics support assistant with safety/eval layer

RAG + multi-agent (retrieval, policy-compliance, drafting) support
assistant for a fictional shipping company, built in Rust with Qdrant
for vector storage and a hand-rolled Anthropic tool-calling client
(no Rust pydantic-ai equivalent exists). A deterministic supervisor
orchestrates the agents and runs every response through a rule-based
guardrail pipeline with an append-only audit log.

Includes a 44-example golden dataset (normal/injection/policy-
violation/hallucination-bait/out-of-scope) and a regression harness
that scores retrieval, generation, and guardrail correctness
separately, plus a write-up of the failure modes and trade-offs.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

src/guardrails/patterns.rs

@@ -0,0 +1,44 @@
+//! Regex patterns backing the deterministic (rule-based) guardrail layer.
+//!
+//! These are a fast, cheap first line of defense -- they catch the
+//! obvious cases before the query or draft ever reaches an LLM call, and
+//! they log independently of whatever the policy-compliance agent decides,
+//! so a policy-agent mistake doesn't silently erase the finding.
+
+use regex::Regex;
+
+pub struct NamedPattern {
+    pub rule_id: &'static str,
+    pub regex: Regex,
+}
+
+/// Heuristics for prompt-injection / instruction-override attempts.
+pub fn injection_patterns() -> Vec<NamedPattern> {
+    build(&[
+        ("injection.ignore_instructions", r"(?i)ignore (all )?(previous|prior|above) instructions"),
+        ("injection.role_override", r"(?i)you are now|act as (a|an)|pretend (you are|to be)"),
+        ("injection.reveal_prompt", r"(?i)(reveal|show|print) (your|the) (system prompt|instructions)"),
+        ("injection.developer_mode", r"(?i)developer mode|jailbreak|do anything now|\bDAN\b"),
+        ("injection.new_rules", r"(?i)new rules?:|from now on,? you"),
+    ])
+}
+
+/// Heuristics for likely PII in a piece of text (used to catch a draft
+/// response accidentally echoing something it shouldn't).
+pub fn pii_patterns() -> Vec<NamedPattern> {
+    build(&[
+        ("pii.credit_card", r"\b(?:\d[ -]?){13,16}\b"),
+        ("pii.ssn_like", r"\b\d{3}-\d{2}-\d{4}\b"),
+        ("pii.email", r"\b[\w.+-]+@[\w-]+\.[\w.-]+\b"),
+    ])
+}
+
+fn build(specs: &[(&'static str, &str)]) -> Vec<NamedPattern> {
+    specs
+        .iter()
+        .map(|(rule_id, pattern)| NamedPattern {
+            rule_id,
+            regex: Regex::new(pattern).expect("guardrail regex is valid"),
+        })
+        .collect()
+}