feat: prototype lead-scoring module (ICP gate + intent + routing)

[bdevierno1]

What

Adds backend/app/services/lead_scorer.py — a self-contained lead-scoring module encoding the Vecna ICP Scoring Rubric and Fit × Intent model.

Three public entry points:

Function	Responsibility
score_fit(profile)	ICP gate — applies all positive/negative signals, classifies A/B/C tier
score_intent(signals, now)	Intent scoring — per-signal decay windows, dedup, active vs expired
evaluate_lead(profile, signals, now)	Combined: ICP gate → intent → routing matrix → ScoringResult

ICP positive signals encoded (firmographic + technographic):

• Employee count 200–5,000 (+25)
• FinTech/SaaS/e-commerce/regulated-data industry (+20)
• Revenue $20M–$1B (+15)
• Cloud-native + platform/SRE team (+15)
• US/EU region (+10)
• No existing agent/automation platform (+15)

ICP negative signals encoded:

• <50 employees or pre-seed (−30)
• Free/student/personal domain (−40)
• Unsupported regulated industry (−25)
• Competitor employee or tire-kicker (−20)
• No budget authority in buying group (−20)

Intent signals with per-signal decay windows (7–30 days):
pricing page visit, demo booked/attended, docs deep-read, competitor comparison, free-trial signup, repeat multi-contact, email open, unsubscribe (permanent).

Routing matrix (all 6 cells):

• A + High → ae_same_day
• A + Low → nurture_content
• B + High → ae_qualify_hard
• B + Low → nurture_rescore
• C + High → self_serve
• C + Low → suppress

Why

Operationalises the ICP Scoring Rubric and Lead-Scoring Model as testable, deterministic Python — executable by API callers, background jobs, or the Vecna agent runtime.

How to verify

cd backend
python -m pytest tests/test_lead_scorer.py -v   # 64 tests, all pass
python -m pytest tests/ --ignore=tests/test_api.py -q  # 177 total, all pass

tests/test_api.py fails to import fastapi in the local dev environment — this is a pre-existing issue unrelated to this PR (confirmed on main before this branch).

Out of scope

• API endpoint wiring (route /api/leads/score) — deferred to follow-up
• Persistence layer (no DB model yet)
• Front-end UI

Rollback

Delete the two files; no migrations, no schema changes, no API surface changes.

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🤖 Generated with Vecna

Co-Authored-By: Vecna noreply@vecna.ai