Declare CB-WP-0012: the render port, tier L, chaos rolled nothing

Declaration 7 of 12. Structural tier L (INTENT stage 1 creates a
capability port); d4 = 1, so no override — the pass runs at full
weight, which is the tier CB-WP-0011's roll deleted.

The leading constraint is AM-4a's 3,750 lines of headroom against
candidate implementations that are all five to six figures. T01 is
required to measure rather than estimate, and to audit the instrument
before recommending any change to the target it reports.

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

workplans/CB-WP-0012-render-port.md

@@ -0,0 +1,139 @@
+---
+id: CB-WP-0012
+kind: product
+title: "Stage 1, second slice: the rendering port"
+status: todo
+---
+
+# Purpose
+
+Tier **L**, the declaration CB-WP-0011 deferred and owed.
+
+```
+structural tier  L   (INTENT stage 1 creates a new capability port)
+chaos            d4 = 1  → no override
+declared tier    L
+```
+
+Declaration 7 of 12 in the calibration window. The CHAOS gate earned its
+first `caught` entry last pass by rolling this same declaration down to S;
+this time it rolls nothing, so the pass runs at full weight — survey,
+adversarial review, ADR, then code. The hard gate applies as stated: **no
+implementation code for the render capability exists before ADR-0007 is
+committed.**
+
+## What this pass owes
+
+INTENT stage 1 is *"Inspectable 2D table — card/token/hand/relationship-
+graph visualization, drag-to-propose, debug inspector, hot-seat play."*
+CB-WP-0011 shipped the debug inspector. This pass owes the other three,
+and the port they hang from:
+
+```
+cb-render-api
+├── cb-render-null
+└── cb-render-???        <- the survey's question
+```
+
+**The leading constraint is AM-4a**: 246,250 lines of 250,000, measured —
+**3,750 lines of headroom**. Every candidate implementation of a 2D table
+is a five- or six-figure line count. This is the first capability in the
+project whose obvious implementation costs more than the entire remaining
+budget, so the survey's first duty is to establish whether that is a real
+obstacle or an artifact of how AM-4a is instrumented.
+
+## Task: survey the render port and its dependency cost
+
+```task
+id: CB-WP-0012-T01
+status: todo
+priority: high
+```
+
+Write `research/CB-RES-0006-render-port.md`.
+
+**Measure, do not estimate.** The candidate line counts must come from
+the same method `tools/dep-weight.py` uses — `cargo tree --edges normal`
+over a real resolved graph, then counted `.rs` lines in vendored source —
+so the numbers are comparable to the AM-4a figure rather than merely
+adjacent. Last pass's correction was a hand-counted number; this pass has
+no excuse for one.
+
+**Measure the marginal cost, not the total.** What AM-4a charges is what a
+candidate adds to a graph that already holds 23 crates. A candidate's
+headline size overstates its cost by whatever it shares with the base.
+
+Cover at minimum: an immediate-mode GUI (`egui`/`eframe`), a 2D game
+framework (`macroquad`), the raw stage-2 stack (`wgpu` + `winit`), a CPU
+rasterizer (`softbuffer` + `tiny-skia`), a terminal UI (`ratatui`), and at
+least one option that is not a Rust toolkit at all.
+
+**Ask whether the instrument is right.** If AM-4a's figure counts code
+that never reaches a shipped binary, the headroom it reports is wrong, and
+that has been true for every pass that has cited it. Check this before
+recommending any budget change — a survey that argues for raising a target
+it has not first audited is arguing in its own favour.
+
+## Task: adversarial review of the survey
+
+```task
+id: CB-WP-0012-T02
+status: todo
+priority: high
+```
+
+Step 2 of the inner loop, run against T01's recommendation rather than for
+it. The review must name, at minimum:
+
+- what the recommended option **cannot** do that a windowed toolkit can,
+  stated concretely rather than as a caveat;
+- the failure mode of building the port around a single implementation
+  when the second-use rule exists precisely to stop that;
+- whether the survey's dependency argument would survive if AM-4a's target
+  were simply wrong, i.e. whether the recommendation is load-bearing on a
+  number the same pass proposes to correct.
+
+A review that ratifies the survey without producing a control the survey
+lacked has not run.
+
+## Task: ADR-0007 — the render port
+
+```task
+id: CB-WP-0012-T03
+status: todo
+priority: high
+```
+
+Record the decision, the rejected alternatives with their measured costs,
+and the controls the implementation must carry. No implementation code
+lands before this commits.
+
+## Task: the port and its first implementation
+
+```task
+id: CB-WP-0012-T04
+status: todo
+priority: high
+```
+
+`cb-render-api` plus `cb-render-null` and the implementation ADR-0007
+chooses, delivering visualization, drag-to-propose and hot-seat play.
+
+**K13 binds here.** The renderer consumes a `Project`ion and can never
+feed back into validation; a drag that proposes a move must go through the
+same command path a CLI move takes. The inspector's coverage gate is the
+precedent for the control this needs.
+
+## Task: evidence
+
+```task
+id: CB-WP-0012-T05
+status: todo
+priority: medium
+```
+
+`evidence/CB-EV-0010-render-port.md`. Carry the standing items: the
+falsifiable prediction from CB-EV-0009 §4 that the trailing-3 meta share
+drops to 0% this pass, SH-3 at 0.0% for a sixth pass, and whether tier L
+at full weight produced anything the rolled-down pass would have missed —
+the CHAOS window's second data point, and the first from a non-override.