imagery: produce positioning assets — craft (rigor) + product classes

[roryford]

Summary

Tracking issue for the visual/imagery assets that back ManifoldKit's positioning.
This is an always-be-launching effort (a continuous stream of proof, not a
one-shot launch), so assets are organized by the story they serve, not by a launch date.

Positioning source-of-truth: docs/POSITIONING.md.
Public-facing "why + how it's built" doc the craft assets embed into:
docs/WHY-MANIFOLDKIT.md.
Screenshot sizes + captions: docs/LAUNCH-BRIEF.md §2.

All existing assets are to be reproduced (the 4 product SVGs and 2 screenshots are
starting points, not finished). The split that matters is build-on vs. from-scratch,
called out per asset below.

Two asset classes

• Craft assets (Lane A — the rigor). Show how ManifoldKit is built to last: the
  fuzz harness, the sabotage suite, the audit tripwires, the migration discipline, the
  enforced module boundaries. Visually from scratch, but the substance is real and
  already running — these are screen-captures of actual tooling, not mockups. This is
  the most differentiated asset class and it has zero assets today. Highest leverage.
• Product assets (Lane B/C — the usefulness). Show the drop-in product: the
  layer-cake, the backend fan, the comparison matrix, the WWDC-timing diagram, and the
  app screenshots. These exist and get reworked.

Directory conventions:
docs/images/craft/ · docs/images/product/ · Example/Screenshots/.
Terminal-derived craft assets: record with asciinema, commit the .cast source beside a
rendered .svg (crisp + lightweight). Diagrams: authored .svg. Screenshots: .png,
light + dark, realistic content.

---

Craft assets (Lane A — from scratch, real source material)

• Fuzz harness finds a bug — docs/images/craft/fuzz-finds-bug.svg (+ .cast).
  Terminal cast of scripts/fuzz.sh driving chat traffic at the backends and surfacing
  the Ollama thinking-token drop (fix(ollama): preserve reasoning model thinking content (currently dropped) #487).
  Caption: "A fuzzer that drives real chat traffic at every backend — this run surfaced a token-drop bug (fix(ollama): preserve reasoning model thinking content (currently dropped) #487) on its first smoke."
• Sabotage suite firing — docs/images/craft/sabotage-suite.svg (+ .cast).
  SABOTAGE=1 swift test --filter ManifoldAuditSabotageSuiteTests: writes a known
  violation into a temp dir and asserts the audit catches it. Green.
  Caption: "Who watches the watchers — a suite that verifies every audit still catches what it claims."
• Audit tripwire rejects a bad commit — docs/images/craft/audit-tripwire.svg (+ .cast).
  A try? added to Sources/; SilentCatchAuditTest fails red with file:line + the
  allowlist hint.
  Caption: "Add a try? that swallows an error and the build rejects it — by file and line."
• SwiftData migration fixture — docs/images/craft/swiftdata-migration.svg.
  Authored diagram: old store → ManifoldMigrationPlan → current schema
  (ManifoldSchemaV6→V9), with the fixture test asserting a clean upgrade.
  Caption: "Versioned schemas + a fixture test that loads an old store and proves it upgrades. SwiftData without the update-day surprise."
• Enforced module boundaries — docs/images/craft/module-boundaries.svg.
  Authored diagram: the 14 trait-gated modules, the enforced edges (UI ✗→ Backends),
  audits drawn as tripwires on the edges (TrafficBoundaryAuditTest).
  Caption: "Fourteen modules, dependency rules the build enforces. The boundaries an agent needs aren't a guideline — they're a failing test."

---

Product assets (Lane B/C — build on existing)

Diagrams (rework the SVGs now in docs/images/product/; export a .png alongside for README/social):

• Layer-cake hero — docs/images/product/layer-cake-hero.{svg,png} (§2.1)
• "One protocol, every backend" fan — docs/images/product/generationstream-backends-fan.{svg,png} (§2.2)
• "vs the field" matrix — docs/images/product/vs-field-matrix.{svg,png} (§2.3)
• WWDC-timing — docs/images/product/wwdc-backend-timing.{svg,png} (§2.4)

Social preview — docs/images/product/social-preview.png, 1280×640, composited
from the layer-cake hero. Upload via repo Settings → Social preview.

• Social preview produced + uploaded.

Screenshots (Example/Screenshots/, light + dark, realistic conversation content; sizes in §2.5):

• macOS chat + sidebar, mid-stream — demo-macos.png (rework)
• iOS chat, streaming — demo-ios.png (rework)
• Model management / download with quantization variants — model-management.png
• RAG citations (CitationsView expanded) — rag-citations.png
• Thinking-block UI (collapsible reasoning) — thinking-block.png
• On-device image-gen (FLUX/SDXL in-chat) — image-gen.png

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Done when

• All 5 craft assets are produced and embedded in docs/WHY-MANIFOLDKIT.md.
• The 4 product diagrams are reworked; the layer-cake hero + the new screenshots are
  embedded in the README (Demo section currently has only demo-macos.png / demo-ios.png).
• The 1280×640 social preview is uploaded to repo settings.

Notes

• Per-asset captions for the product diagrams are written verbatim in
  LAUNCH-BRIEF.md §2; craft-asset captions are above.
• The craft assets are the priority — they're the differentiated, durable class and they
  don't exist yet. Producing them is "point a camera at the rigor that already runs."