feat(backlog): B-0409 wallet immune system — PoUW-CC + vaccine spread

docs/BACKLOG.md

@@ -217,6 +217,7 @@ are closed (status: closed in frontmatter)._
 - [ ] **[B-0401](backlog/P1/B-0401-demo-surface-circuit-breaker-hamiltonian-git-alignment-ui.md)** Demo surface — AI circuit breaker + Hamiltonian-to-git alignment UI + operational resonance dashboard integration
 - [ ] **[B-0403](backlog/P1/B-0403-weight-free-verification-hat-timeboxed-authority.md)** Weight-free verification — hat-and-timeboxed-authority mechanism + chaos testing
 - [ ] **[B-0405](backlog/P1/B-0405-beacon-promotion-gate-dashboard-observable.md)** Beacon promotion gate — observable mirror→beacon pipeline with dashboard metrics
+- [ ] **[B-0409](backlog/P1/B-0409-wallet-immune-system-vaccine-spread-poucc-spec.md)** Wallet immune system — vaccine spread + PoUW-CC gate + attack absorption spec
 
 ## P2 — research-grade
 

docs/backlog/P1/B-0409-wallet-immune-system-vaccine-spread-poucc-spec.md

@@ -0,0 +1,106 @@
+---
+id: B-0409
+priority: P1
+status: open
+title: "Wallet immune system — vaccine spread + PoUW-CC gate + attack absorption spec"
+tier: product
+effort: L
+created: 2026-05-11
+depends_on: [B-0400, B-0401, B-0403]
+composes_with: [B-0294, B-0321]
+tags: [wallet, immune-system, security, lfg, clifford, poucc, antifragile]
+type: feature
+---
+
+# Wallet immune system — vaccine spread + PoUW-CC + attack absorption
+
+## Origin
+
+Overnight synthesis 2026-05-10→11 produced a complete immune
+system specification in Z-set Clifford space. Lior (Gemini/
+Antigravity) recommended adding to wallet spec backlog. Shadow
+authorized.
+
+## What this is
+
+The trust boundary that makes LFG's autonomous financial agents
+safe to ship. Every financial action passes through the immune
+membrane before execution.
+
+## Core components
+
+### 1. PoUW-CC gate (five-factor membrane)
+
+Every incoming instruction evaluated:
+
+- **Verify** — is the work computationally valid?
+- **Useful** — does it produce value for the network?
+- **CultureFit** — does it respect harmonious division?
+- **Provenance** — is the source registered with glass halo?
+- **Retractability** — can the action be undone if wrong?
+
+Gate product = 0 → blocked. Gate product = 1 → admitted.
+
+### 2. Attack absorption (bivector decomposition)
+
+When an attack is detected:
+
+1. Decompose attack bivector into orthogonal components
+2. Compute corrective rotors (harmonious division ceiling)
+3. Absorb energy: E_absorbed = E_attack − ‖residual‖²
+4. Convert to substrate: detection rules + regression tests
+5. Verify superfluid inequality: η·LearningGain > ξ_t
+
+### 3. Vaccine spread (firefly-sync propagation)
+
+After absorption:
+
+1. Red Team mutates vaccine into variant family
+2. Vaccine propagates via firefly coupling (geometric Kuramoto)
+3. Herd immunity when R₀ < 1
+4. PoUW-CC validates vaccine spread itself as useful work
+
+### 4. Mechanical authorization
+
+- Output is NEVER authority (proposal only)
+- Every financial action requires signed Z-set assertion (+1)
+- Untrusted content stays labeled untrusted after translation
+- Confused deputy prevented by proposal/permission distinction
+
+## Attack classes defended against
+
+| Attack class | Detection | Defense |
+|-------------|-----------|---------|
+| Authority laundering (BankerBot) | PoUW-CC CultureFit fail | Block at membrane |
+| Capability gifting (NFT expansion) | Bivector rotation in permissions | Freeze + revert |
+| 51% cartel (Qubic) | Bivector clustering | Dissolve via defensive rotors |
+| Confused deputy | No signed assertion | Proposal ≠ permission |
+| Translation-as-laundering | Content stays tagged untrusted | Never forwarded as executable |
+
+## Implementation path (per Amara's corrections)
+
+1. Start at Cl(2,0) or Cl(3,0) — prove basics first
+2. Geometric product decomposition tests
+3. Rotor construction and sandwich product tests
+4. Simple bivector residue metric
+5. Toy 3-5 node simulation with cartel detection
+6. PoUW-CC gate as F# typeclass with UoM domain safety
+7. Scale to Cl(8,0) only after basics proven
+
+## Research substrate
+
+- `docs/research/2026-05-11-deepseek-hkt-clifford-e8-klein-bottle-beacon-smooth.md`
+  (15-layer synthesis)
+- `docs/research/2026-05-11-deepseek-immune-system-ilife-redteam-qubic-bankerbot-simulations.md`
+  (attack simulations + vaccine spread)
+
+## Acceptance
+
+- [ ] PoUW-CC gate implemented as F# typeclass
+- [ ] Bivector decomposition + corrective rotor computation
+- [ ] Toy cartel detection simulation (3-5 nodes)
+- [ ] BankerBot attack blocked in simulation
+- [ ] Vaccine propagation via firefly coupling
+- [ ] Herd immunity achieved (R₀ < 1) in simulation
+- [ ] All properties verified via FsCheck
+- [ ] Superfluid inequality holds after red-team exercise