Thing 2.0 target: rationale, shape and the consumer contract

Campaign thing2. Rulings thing2-one-solver-taffy, thing2-thing-owns-text,
wire-rename-freeze-fold.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/thing2-target.md

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+# Thing 2.0 target
+
+Campaign `thing2` in the eureka mind. This page holds the rationale and the
+design truths the rebuild produces. The typed `thing2:target` holds the
+invariants, the not-in-scope list and the canonical implementations; the
+rulings are in the mind and are cited here by id, never restated.
+
+## Why
+
+Thing 1 handed layout to each host's own engine (CSS flexbox in the browser,
+Flutter widgets, Unity UI Toolkit's Yoga), so there were as many layout specs
+as renderers and the browser was the oracle in practice. Its contract grew
+domain kinds (`inventory.grid`, `vn.stage`, 41 kinds in the fixtures) that every
+lowerer in five languages had to implement. Parity was screenshots and gap
+ledgers, not geometry. Live state binding, pointer resolution and command
+results lived in each renderer, which is where the July failures came from
+(views that had to reload, failing commands, schema-rejected results). Evidence:
+`docs/research/thing2-foundation-prior-art.md`.
+
+Operator, 2026-10-10: "More Things, fewer things."
+
+- **More Things:** every surface is a composition of Things, published as Thing
+  Script. An inventory grid, a VN stage or an Odin wall is a composition, not a
+  contract kind.
+- **Fewer things:** a small closed primitive set, one layout solver, one closed
+  render-command list, thin backends, far fewer repos.
+
+## Shape
+
+```
+typed retained document (Thing Script, bound to typed CultMesh state)
+  -> Thing core: Taffy layout, Parley text, focus, editing/IME state, AccessKit tree
+  -> closed render-command list (+ accessibility tree)
+  -> thin backends: draw, and bridge input/IME/accessibility to the platform
+```
+
+Rulings in force: `thing:ruling:thing2-one-solver-taffy`,
+`thing:ruling:thing2-thing-owns-text`, `thing:ruling:wire-rename-freeze-fold`,
+`thing:ruling:operator-compat-rebuild`, `thing:ruling:hold-renames-for-thing2`.
+Text, IME and accessibility evidence:
+`docs/research/thing2-text-input-a11y-prior-art.md`.
+
+## The consumer contract
+
+Consumers (provider daemons, Verse daemons, CultLib runtimes, game hosts) never
+see Taffy, Parley or render commands. They depend on four things only:
+
+1. **Thing Script** — the typed documents they publish: primitives plus shared
+   compositions.
+2. **Binding** — how a surface points at typed CultMesh state and receives
+   live updates.
+3. **Commands** — how input returns as a typed command with a schema-checked
+   result.
+4. **Advertisement** — how a provider announces itself to Odin.
+
+Each waiting consumer migrates by one port cut onto this contract, which also
+carries its rename to `gamecult.thing.*` (rename table T and edge table E1-E7 in
+`docs/thing-campaign.md`). The consumer census sizes the floor of Thing Script;
+Thing is a general library, so capability a reasonable consumer would expect is
+not cut for lack of a current caller.
+
+## Open before any cut is mapped
+
+- The identity, lifecycle and authority table for every persistent kind
+  (model page in the prose map).
+- The consumer census: what each waiting consumer publishes, binds and commands
+  today.
+- Where Thing 2.0's code lives (a fork, to be put with prior art).
+- Which backend lands first for cutover: at minimum web, plus TUI for agents.