refactor(ios): carry provider acquisitions through one presentation owner

[thymikee]

Parent: #2188

Follows: #2195

Blocks: #2196

Outcome

Finish the Appium/WebDriver and Limrun convergence by carrying their typed acquired iOS snapshot
input through the snapshot runtime to one host-side presentation owner. Provider adapters should
parse vendor facts and limitations; they should not each plan, present, translate engine errors,
render residue warnings, and then collapse the result back into the legacy snapshot shape.

This is a deletion-first follow-up to #2195. It must make the shared interface cheaper and harder
to use inconsistently before the Simulator bridge adopts it.

Exact scope

• Define the smallest internal snapshot-runtime result that can carry stage: acquired plus typed
  acquisition facts from a provider adapter to one host presentation owner. Keep it internal; do
  not add required public RPC fields.
• Make the Appium/WebDriver and Limrun iOS adapters return vendor facts, viewport evidence,
  lineage, truncation knowledge, and typed residue through that carrier.
• Present both providers exactly once at the shared host boundary and preserve the existing public
  SnapshotResult/daemon output shape after presentation.
• Add explicit producer capability for truncation evidence. Derive unavailable facts centrally;
  do not infer truncation knowledge from acquisition-depth or presentation ownership.
• Delete WebDriver's attach-ref/strip-ref round trip and production wrappers/types that exist only
  so tests can inspect an intermediate publication.
• Delete provider-local request/plan/presentation orchestration, duplicate residue construction,
  duplicate warning rendering, and divergent engine-error translation where the shared owner can
  express the same behavior.
• Reuse the shared viewport-root resolver for Limrun while retaining its valid device-info fallback.
• Keep WebDriver Android's current derived source semantics, but isolate them as Android-owned
  behavior. Do not thread a legacy mode through iOS or scroll-frame code that does not need it.
• Move the real Limrun provider-runtime to daemon/public regression into the provider-scenario
  harness if that removes custom handler-test scaffolding without weakening the route it proves.

Required simplification

• Start from the merged refactor(ios): route Appium snapshots through engine #2224 and refactor(ios): converge Limrun snapshots through engine #2222 implementations and report gross additions/deletions for
  production and tests separately.
• The final production diff must be net-negative against current main. New shared code must
  delete more provider/runtime code than it adds.
• Prefer one typed construction/presentation path over a configurable helper with provider-name
  branches. Do not replace duplicate code with a generic bag of callbacks.
• Remove obsolete tests after equivalent closest-negative and production-route evidence exists.
  Do not keep tests whose only purpose is pinning deleted wrappers.

Non-goals

• No Simulator bridge implementation, backend selection, fallback, generation circuit,
  runner-demand, proxy, open/relaunch, or physical-device change.
• Do not perform refactor(ios): prune converged snapshot paths and close release gates #2199's final snapshot-state pruning: presentationOwner, the producerless
  legacy presentation branch, backendScopesAfterWire, and direct legacy presenter removal remain
  owned by the later routing/pruning sequence unless this change can delete a provider-only arm
  without affecting the bridge plan.
• No Android output or interaction behavior change, provider SDK upgrade, public CLI flag, public
  backend flag, or required wire field.
• Do not merge Appium and Limrun parsers into one vendor-shaped parser.

Acceptance and evidence

• Appium and Limrun each prove their real provider adapter/runtime path reaches one shared host
  presentation owner exactly once.
• Regular/raw, depth, scope, interactive-only, viewport failure, unavailable hittability, and
  unknown truncation remain behaviorally consistent with refactor(ios): build and prove the converged snapshot engine #2191 and refactor(ios): converge Appium and Limrun acquisition adapters #2195.
• Unknown truncation remains absent through daemon, JSON output, and client without downstream
  inference from acquisition depth.
• A planted violation proves a provider cannot present before the shared owner or discard typed
  residue and still pass.
• Android WebDriver parsing and scrolling retain focused positive coverage.
• The PR body records removed wrappers/branches/tests, production and test line deltas, CI Size/npm
  unpacked delta, and why any remaining provider-specific logic cannot live at the shared owner.
• Focused provider/capture-kit/contracts/runtime tests, layering, Fallow, and exactly one
  pnpm check:affected --run pass on the final pre-push head. GitHub exact-head CI is authoritative.
• Publish one ready-for-review PR targeting main; do not merge it.

Worker stop conditions

• Stop if the design requires public wire evolution, bridge routing, or changes to Android behavior.
• Stop and report if the proposed shared abstraction is not net-negative or merely replaces direct
  code with callbacks, flags, casts, or provider-name switching.
• Stop if the real provider-to-daemon regression would be weakened to a mocked helper-only test.
• Do not preserve compatibility scaffolding for the unreleased refactor(ios): route Appium snapshots through engine #2224/refactor(ios): converge Limrun snapshots through engine #2222 internal shapes; verify
  with git tag --contains before claiming compatibility is required.