Add simulator replica, persistence, planet scan, README; split empire state out of the repo

- tools/simulate.py + puga/simulate.py: replica of PRUNplanner's simulator (flows and
  efficiency verified against screenshots), reports real new capex (planned minus built)
- tools/scan.py: staffing variants, freight, HQ/experts, --planet mode, demolish-later,
  --min-n as a pure market-size filter, --json output
- tools/history.py, tools/persistence.py: margin history and short-horizon payback checks
- tools/plan_push.py: guarded delete; tools/state.py: syncs to empire/
- README with features and setup; CLAUDE.md made generic
- Own-empire material (profile, state, plans, notes) moved to gitignored empire/;
  generic examples in plans/examples and state/company.example.yaml

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

state/company.example.yaml

@@ -0,0 +1,12 @@
+# Example only. `tools/state.py sync` writes the real file to private/state/company.yaml (gitignored).
+as_of: "2026-01-01 00:00Z"
+company: {name: Example Co, ticker: EXC, user: yourname, faction: ANTARES, home_cx: AI1, currency: AIC}
+licence: FREE
+hq: false                     # true if you have a corporation HQ (adds x1.1 efficiency)
+permits: {used: 1, total: 2}
+cash: {AIC: 10000}
+bases:
+  - name: Example
+    planet: XX-000a
+    cogc: METALLURGY
+    buildings: {SME: 2, HB1: 1}