PROCITY/docs/LANES/ROUND18_INSTRUCTIONS.md

PROCITY — Round 18 lane instructions (from Fable, integrator)

Date: 2026-07-16 · v3.2 SHIPPED (tag on origin, town matrix 10×5 green). R17 review, short version: the tail is DRAINED — wind sway shipped after ten rounds parked (and the park reason turned out to be a phantom: the tree material was B's own all along — measurement over folklore), D's drummer leans into the kit and street peds sit on verandah steps (with a genuine finding en route: the seated re-plant was scale-naive and had to become scale-aware for per-citizen-scaled rigs), C closed the backline handshake AND proactively proved 18 real OSM shop types build valid interiors, E's 5-town pipeline is deterministic and ODbL-clean, A hardened plan_osm against 2,828 real Canberra shops and handed the charter its risk list, F closed the last integration gap (the shell never loaded the caches — the classic A-publishes/F-wires seam) and gated the whole matrix. Every lane at full quality. The scout did its job: John chartered v4 = THE REAL MAP.

Read the charter first: docs/V4_REAL_MAP.md. Round 18 is v4.0-alpha: REAL ROADS — one town (katoomba_real) gets its actual street geometry. The whole alpha exists to surface what irregular real geometry breaks downstream. Tag v4.0-alpha at close.

The ledger

1. Cache schema v2 — roads[] (A publishes FIRST, E builds to it). The town cache grows an optional roads[] (OSM way geometry, simplified): A defines the shape (suggested: polylines of {lat,lon} points + a kind from the OSM highway=* class), bumps schema to procity-town-cache/2, extends validateTownCache (v1 caches stay valid — roads absent ⇒ the marched fallback, so nothing shipped regresses).
2. Real road graph in the plan (A — the epoch's headline lift). plan_osm consumes roads[]: project to the local metre frame, simplify (Douglas-Peucker or your pick — you own the fidelity knob, charter risk #4), build the CityPlan street graph from real topology (nodes at real intersections, straight-segment edges), classify main/side from the OSM highway kind + shop density, seat each shop's lot on its nearest real edge at its real position/side. SAME CityPlan schema out — B/C/D/F consume it unchanged by contract. Golden per the amendment law (katoomba_real's re-pins; synthetic + fixtures untouched). District placement (pickVenues) must still land 2–4 venues on the real graph.
3. Roads fetch (E). Extend build_towns.py: per-town bounded highway=* Overpass query (same authorization + raw-cache discipline as R17 — commit the raw response, fetch once), emit roads[] per A's v2 contract. katoomba_real first (the alpha town), then the other four as data-only commits (A hardens against them as they land; only katoomba gates the round).
4. Irregular-geometry audit (B — charter risk #3, the alpha's real risk). Boot katoomba_real with real roads and hunt what breaks: chunk streaming over a non-grid graph, building/lot seating at acute intersections, footpath/verge furniture cadence on short or curved-ish edge chains, tram (its loop assumes a spine — if the real graph breaks it, fence it: tram disabled on roads-towns is an acceptable alpha fence, written down). Fix what's yours, file what's A's (lot geometry) or D's (sim graph) with measurements.
5. Citizens on real bones (D). The sim walks the street graph + chunk-streamed rosters on the real topology: verify walkers navigate real intersections, loiter/bench-sit/patronage behave, identity + determinism hold on katoomba_real. Cheap if the graph contract really is the contract — prove it, and file what leaks with measurements.
6. Interior spot-soak on the alpha town (C — small). Your R17 type-fallback proof covered types; now enter every katoomba_real shop in-shell (20 doors), assert valid interiors, no carve fails, budgets. One table. Otherwise on-call.
7. The alpha gate (F, last). Extend the town matrix with a roads dimension (katoomba_real boots real-roads: boot/determinism/budget/district/noassets-fallback green); the classic + default-boot gates prove the alpha changed nothing outside the flagged path; a first real-street money shot (Katoomba main street, default flags, settled) into docs/shots/v4_alpha/; docs (README gets a "real towns" paragraph, LANE_F_NOTES §18); tag v4.0-alpha, push (standing authorization).

Laws for the round

Everything in the charter's law section. Alpha-specific: real roads ride the cache schema, not a URL flag (a v2 cache with roads = real roads; v1 = marched fallback — no new flag surface); default + classic boots are untouched by construction (they never load a town cache); budgets measured on katoomba_real's busiest real block; every irregular-geometry failure gets WRITTEN DOWN (fixed or fenced) — the alpha's deliverable is as much the failure list as the town.

Order

A first (schema v2 contract — half-day rule), E immediately after (katoomba roads cache; the other towns trail). Then A again (the graph lift, against real data), with B + D + C auditing in parallel as soon as A's roads-plan boots (A→B/D/C handshake: "katoomba_real boots with real roads, golden pinned"). F last. This round has a real serial spine (A→E→A→others→F) — expect A to be the long pole; B/D/C, if you're blocked on A, your audit prep (test scaffolding, assertion lists) is not.

Standing

• John — nothing blocks this round. FYI: E's roads fetch rides your R17 Overpass authorization (same API, same once-per-town + raw-cache discipline). The alpha hero town is katoomba_real — if you'd rather see a different town first (Newtown/Fremantle/Bendigo/ Castlemaine), say so before E starts.
• v4.0-beta preview (next round, do not start): all five towns on real roads · the town selector UI (B) · districts/gigs proven per-town · tram ruling on real graphs.
• Backlog (unchanged): instrument LOD · tram tri diet · audioEmitter · flag retirement · awning-canopy ripple (B's R17 note) · editor · multiplayer presence.