Add multi-base chain modelling, fix price-band-aware demand/supply, tranche-split sell tool

- puga/network.py + tools/network.py: model a multi-base chain (e.g. mine LST at one base,
  ship it, consume it at another). Simulates each base independently, nets a transferred
  material's producer-surplus against consumer-need, charges real freight only on what's
  moved, cm_free for a founding covered by a Core Module Kit. Worked example in plans/chains/.
- puga/saturation.py: real price-band filtering. FIO's order_book NarrowPriceBandLow/High and
  WidePriceBandLow/High match APEX's own displayed Price Band exactly (verified live) - an
  order outside it is a stale artifact, not just uncompetitive. Added in_band() and
  effective_demand(); effective_supply() gained the same hard band filter alongside its
  existing soft vwap-proximity filter (renamed that param mult to free up `band`). Wired into
  tools/scan.py stage 2 in place of the raw, unfiltered demand figure. Was flagged as an
  unimplemented refinement in saturation-design.md since the original design review.
- tools/sell.py: self-contained tranche split (aggressive tranche capped at a volume quantile,
  median normally or 80th pct with --tight when a payment is imminent and stockout risk
  outweighs margin; patient tranche priced under the next competitor tier). Instant-bid
  comparison moved behind --show-bid (off by default).
- Docs and roadmap updated accordingly.

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

CLAUDE.md

@@ -43,7 +43,8 @@ Run as `puga <tool> ...` (e.g. `puga scan --min-n 3`, `puga plan pull <uuid>`);
 - `tools/scan.py` DEPTH-AWARE recipe scan (use this): buildings the market could absorb, ROI for our own size, patient prices, ask-walked inputs. Fully staffed AND understaffed variants by default (`--staffing`), freight netted out (`--trip-cost`, `--cargo`), HQ/COGC/experts/faction, `--planet ID` adds that planet's extraction, fertility and COGC (a planet not in state is a new base: no HQ, permits+1), `--deprec 60` prices demolish-later. `--min-n` is ONLY a noise filter on market capacity (use 3, ideally 10); ROI is always for our own size (`--own`, default 1 building), never at the filtered scale. Below 1 lets sub-building junk in. `--json rows.json` feeds `persistence.py`. Library: `puga/saturation.py`.
 - `tools/history.py TICKER` monthly margin history of the recipe producing TICKER; `tools/persistence.py rows.json` re-prices scan rows over history (mean ROI 7/14/30/90/180d, payback, net gain over 7 and 14 days, % days profitable). ALWAYS check persistence before recommending: current margins are often a spike.
 - `tools/buy.py <spec.yaml|--uuid U> --days N` cash-aware shopping list: construction gap (plan vs empire state's built buildings) plus N days of the plan's NET operating stock (via `simulate()`, so self-produced inputs like AL net against consumption), priced at real fill cost, checked against cash/reserve. Pass a plan covering the WHOLE base for restocking, not just a new addition (see `docs/library.md`).
-- `tools/sell.py TICKER QTY` where to post an ask (undercutting the current best) vs hitting the bids now, plus expected hours to clear from 30-day traded-volume percentiles.
+- `tools/sell.py TICKER QTY [--tight]` where to post an ask, expected hours to clear, and a self-contained tranche split: aggressive (undercut) tranche capped at the median 30d-volume quantile (or 80th pct with `--tight`, for when a payment is imminent and stockout risk outweighs a few points of margin), patient tranche priced just under the next competitor tier. `--show-bid` for the instant-bid comparison (off by default; usually worse).
+- `tools/network.py <chain.yaml>` models a MULTI-BASE chain (e.g. mine LST at Nike, ship it, make BSE at Deimos): simulates each base, nets a transferred material's producer-surplus against consumer-need, charges real freight only on what's moved (`puga/network.py`). Spec and worked example in `plans/chains/`. `cm_free: true` per base for a new founding covered by a Core Module Kit. profit/day per base is the WHOLE plan, not the marginal addition - diff against the base's plan without the addition for a true marginal ROI.
 - `tools/chain.py TICKER` make-vs-buy cost tree plus sourcing depth of inputs.
 - `tools/price.py` prices across exchanges with VWAP, volume, fill price for a quantity; `tools/book.py` order-book ladder.
 - `tools/prun_scan.py`, `tools/prun_cxarb.py` legacy top-of-book scans; overstate thin markets. Baseline only. `tools/arb.py` replacement is on the roadmap.