feat: implement Pillars 2-4 and fix a production false-positive in Pillar 1

Pillar 1 v1.1 (shipped earlier) flagged benign browsing bursts as
beaconing: on short captures, grid periods longer than the observed
span never complete a cycle, so significance saturates to 1 and the
score sticks at exactly 0.5. v1.2 caps the grid at a third of the
observed span, requires a minimum number of completed cycles, and
excludes protocols that are periodic by nature (NTP, DNS, mDNS,
ICMP). Validated against 300 seeds per scenario: false positives on
bursty traffic drop from the 290-300/300 that v1.1 produced to 0/300,
with every beacon-detection scenario scoring unchanged.

Add Pillar 2 (persistent/long-lived sessions, with Zeek's fragmented
TCP sessions rejoined after a 5-minute gap), Pillar 3 (DNS tunneling
via Shannon-entropy information volume per subdomain per hour; the
Jensen-Shannon divergence was measured and does not separate tunnels
from benign CDN subdomains, so it stays in the evidence at zero
weight instead of in the score), and Pillar 4 (deterministic
noisy-OR fusion across the three pillars).

The fusion formula was validated against 8 labeled real-traffic
vectors (IoT-23, CTU-Normal) with tolerance <= 1e-4. A known
limitation is kept, not hidden: a benign Philips HUE bulb's strict
periodic polling and a 21.9h session score it above three real C2
hosts. No weight or threshold was tuned to mask this; it is
documented in the architecture docs instead.

Also fixes real bugs found along the way: ingest_dir's partition
count summed file names instead of distinct dates, DuckDB errors
were counted as bad rows, /api/alerts always returned an empty list
regardless of the last analysis, and the dashboard still claimed
every pillar was unimplemented.

Restores four design corrections that were missing from
docs/architecture.md (KL to Jensen-Shannon, the persistent-session
detector, the JA4 licensing boundary, and deterministic reduction
order), and catalogs the public datasets used for validation
(IoT-23, CTU-Normal, Mendeley DTQBC) with their licenses and SHA-256
checksums under research/validation/.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VAyr8d7HuAdUGB6aA5xmDD

research/validation/zeekstat.py

@@ -0,0 +1,38 @@
+import sys, collections
+def read(path):
+    fields=None; rows=[]
+    for line in open(path, errors='replace'):
+        line=line.rstrip('\n')
+        if line.startswith('#fields'): fields=line.split('\t')[1:]; continue
+        if line.startswith('#') or not line: continue
+        p=line.split('\t')
+        rows.append(dict(zip(fields,p)))
+    return rows
+def f(x):
+    try: return float(x)
+    except: return None
+for path in sys.argv[1:]:
+    rows=read(path)
+    tup=collections.defaultdict(list)
+    for r in rows:
+        if r.get('proto')!='tcp': continue
+        tup[(r['id.orig_h'],r['id.resp_h'],r['id.resp_p'])].append(r)
+    out=[]
+    for k,rs in tup.items():
+        ivs=sorted((f(r['ts']), f(r['ts'])+(f(r['duration']) or 0)) for r in rs)
+        # union length
+        tot=0; cs,ce=ivs[0]
+        for s,e in ivs[1:]:
+            if s<=ce: ce=max(ce,e)
+            else: tot+=ce-cs; cs,ce=s,e
+        tot+=ce-cs
+        mx=max((f(r['duration']) or 0) for r in rs)
+        ob=sum(int(r['orig_bytes']) if r['orig_bytes'].isdigit() else 0 for r in rs)
+        rb=sum(int(r['resp_bytes']) if r['resp_bytes'].isdigit() else 0 for r in rs)
+        states=collections.Counter(r['conn_state'] for r in rs)
+        out.append((tot,mx,len(rs),k,ob,rb,dict(states.most_common(3))))
+    out.sort(reverse=True)
+    allts=[f(r['ts']) for r in rows]
+    print('==',path, 'tcp tuples',len(out),'span_h %.2f'%((max(allts)-min(allts))/3600))
+    for o in out[:8]:
+        print('  union=%.0fs max=%.0fs n=%d %s ob=%d rb=%d %s'%o)