Add Population Pressure Valve system to Egypt

Core mechanic: two valves (emigration vs domestic spending) with three meters:
- Domestic Pressure (high = revolution)
- Roman Displeasure (high = intervention/annexation)
- Fiscal Health (low = bankruptcy → cascade)

Player walks tightrope between all three:
- Too much emigration → Rome intervenes
- Too much spending → fiscal collapse
- Too little of both → revolution

Each faction prefers different valve settings
Win states: Economic Recovery (long, safe) or Independence First (risky, fast)
Fail state: Roman annexation (game over?)

Interaction with Italian Empire player: emigration events fire in both countries

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

1 files changed, 147 insertions, 0 deletions

diff --git a/COUNTRIES_V3/EGYPT.md b/COUNTRIES_V3/EGYPT.md
index 168973f..be5e01b 100644
--- a/COUNTRIES_V3/EGYPT.md
+++ b/COUNTRIES_V3/EGYPT.md
@@ -139,6 +139,153 @@ Egypt's surplus population flows into the Roman Empire:
   → Egyptian player deals with brain drain + remittances + diaspora politics
 ```
 
+## Core Mechanic: The Population Pressure Valve (人口泄压阀)
+
+The central gameplay loop of Egypt. Every decision revolves around this system.
+
+### The Dilemma
+```
+Egypt has far more people than its economy can support.
+Surplus population creates: unemployment → crime → unrest → factional extremism → state collapse
+
+Two "valves" to release pressure:
+  VALVE 1: Let people LEAVE (emigration to Roman Empire)
+  VALVE 2: SPEND money to keep people fed (bread subsidy / public works)
+  
+  Both valves have costs:
+```
+
+### Valve 1: Emigration (Open the Border)
+```
+Benefits for Egypt:
+  ├ Fewer mouths to feed → domestic pressure reduced
+  ├ Remittances from diaspora (small but real income)
+  ├ Safety valve against revolution (angry young men leave instead of rioting)
+
+Costs for Egypt:
+  ├ Brain drain (educated/skilled people leave first)
+  ├ National humiliation ("our people beg in foreign streets")
+  ├ ROME IS FURIOUS:
+  │  Roman governor demands Egypt stop the outflow
+  │  Italian cities dealing with Egyptian crime/poverty
+  │  Anti-migrant sentiment strengthens Italian nationalists
+  │  Rome threatens: "control your people or we tighten the protectorate"
+  │  → Roman Displeasure meter rises
+  │  → At maximum: Rome intervenes directly (suspend parliament? install new governor? annex?)
+  └ Diaspora becomes politically active (exile movements, revolutionary cells in Italian cities)
+```
+
+### Valve 2: Domestic Spending (Feed Them)
+```
+Benefits for Egypt:
+  ├ Population stays calm (bread keeps people quiet)
+  ├ Rome is satisfied (no migrant crisis)
+  ├ Public works employ some surplus labor (canals, roads, factories)
+
+Costs for Egypt:
+  ├ FISCAL DRAIN: bread subsidy + public works = enormous cost
+  │  → Budget deficit grows every year
+  │  → Must borrow (from Rome? from Ilkhanate? both want leverage)
+  │  → Debt spiral → eventual fiscal collapse
+  ├ Doesn't solve the root problem (population still growing)
+  └ Each faction wants the spending directed differently:
+     Clergy: build mosques/schools
+     Aristocracy: military spending
+     Modernizers: factories
+     Peasants: land reform + direct aid
+     → Spending allocation = factional battleground
+```
+
+### The Balancing Act
+```
+          ┌── Emigration (open valve 1) ──┐
+          │                                │
+     Egypt's                          Rome's
+     domestic                         displeasure
+     pressure ──── THE PLAYER ────── meter
+          │        balances          │
+          │        between           │
+     ┌── Spending (open valve 2) ──┐ │
+     │                              │ │
+  Fiscal                         Faction
+  health                         demands
+  meter                          (who gets $?)
+  
+  TOO MUCH EMIGRATION → Rome intervenes → loss of autonomy/annexation
+  TOO MUCH SPENDING → fiscal collapse → can't pay army → coup/revolution
+  TOO LITTLE OF BOTH → domestic explosion → revolution anyway
+  
+  WINNING CONDITION:
+  → Balance long enough to either:
+    A. REBUILD ECONOMY: industrialize Cairo, employ surplus, become self-sustaining
+       → eventually restart bread subsidy from OWN revenue (not imports)
+       → population pressure naturally subsides as economy absorbs workers
+       → Egypt stabilizes → can negotiate better terms with Rome
+    
+    B. GAIN INDEPENDENCE: exploit Rome's succession crisis (Napoleon dies)
+       → while Rome is distracted, declare independence
+       → but must be economically viable first or independence = immediate collapse
+       → independence without economic reform = jumping from frying pan to fire
+```
+
+### Interaction with Factions
+```
+Each faction has a PREFERRED valve setting:
+
+Roman Administration: "CLOSE THE BORDER. Spend more. We'll loan you money." (trap: debt dependency)
+Mamluk Aristocracy:  "Close the border. Military spending. We restore order." (trap: military coup)
+Sunni Populists:     "Expel the Romans! Open/close border irrelevant — revolution fixes everything!" (trap: chaos)
+Pan-Arabists:        "Open borders to ARAB countries, close to Rome." (trap: unrealistic)
+Modernizers:         "Controlled emigration + industrial investment. Balance both." (trap: too slow, factions lose patience)
+Peasants:            "We don't care about borders — give us LAND and FOOD." (trap: land reform triggers aristocratic/clerical backlash)
+```
+
+### The Meters (UI Concept)
+```
+Three bars the player must watch constantly:
+
+[████████░░] Domestic Pressure (high = revolution imminent)
+  ↑ rises from: unemployment, hunger, factional anger
+  ↓ falls from: emigration, spending, successful reforms
+
+[██░░░░░░░░] Roman Displeasure (high = intervention imminent)
+  ↑ rises from: emigration, anti-Roman actions, instability
+  ↓ falls from: border control, cooperation, debt acceptance
+
+[████░░░░░░] Fiscal Health (low = bankruptcy imminent)
+  ↑ rises from: industrial revenue, trade, foreign aid, austerity
+  ↓ falls from: bread subsidy, public works, military spending, debt service
+
+If ANY meter maxes out → crisis event:
+  Domestic Pressure max → revolution (faction-dependent outcome)
+  Roman Displeasure max → Roman intervention (annexation? puppet swap? military crackdown?)
+  Fiscal Health zero → bankruptcy → all other meters spike → cascading collapse
+```
+
+### Win States
+```
+ECONOMIC RECOVERY (long game, 20-30 years):
+  → Industrialize enough to employ surplus population
+  → Agricultural reform to reduce food import dependency
+  → Restart bread subsidy from domestic revenue
+  → All three meters stabilize in safe zone
+  → THEN: negotiate better terms with Rome (from position of strength)
+  → OR: declare independence when Rome is distracted (Napoleon's death)
+
+INDEPENDENCE FIRST (risky, fast):
+  → Exploit Napoleon's death (~1837-1840)
+  → Declare independence during succession crisis
+  → But economy isn't fixed yet → immediate pressure spike
+  → Must then fix economy while also defending sovereignty
+  → High risk, high reward
+
+SURRENDER (fail state):
+  → Accept full Roman annexation
+  → Egypt ceases to be a playable nation
+  → Becomes a Roman province (like Libya/Algeria)
+  → Game over? Or continues as a liberation movement?
+```
+
 ## V3 Gameplay: Survival Mode
 
 ### Opening State (1836)