refactor(daemon): separate open-target planning from platform mechanics

[thymikee]

Purpose

Child of #2278 (audit area: open-target planning). src/platform-runtime-open-target.ts mixes a neutral open plan/result policy with platform mechanics:

• neutral: resolveRequestedOpenSurface, validateOpenRelaunchTarget, resolveSessionAppBundleIdForTarget
• Apple mechanics: resolveSoleForegroundIosApp (sole-booted-simulator/foreground-app probe)
• Android mechanics: resolveAndroidPackageForOpen, inferAndroidPackageAfterOpen

Two classified daemon edges (R74 inventory) consume this file:

• src/daemon/session-lifecycle/internal/session-open-prepare.ts → resolveRequestedOpenSurface, validateOpenRelaunchTarget
• src/daemon/handlers/session-selector-dispatch.ts → resolveAndroidPackageForOpen, resolveSessionAppBundleIdForTarget

Required behavior

• Separate the pure open plan/result from the platform implementation only when that creates a deeper interface and removes duplicated policy; preserve one construction path (one resolver producing the open plan — no second).
• The daemon open prepare and selector-dispatch code imports only the neutral plan/policy surface.
• Android package resolution moves behind the Android owning seam (package facts/runtime interface in packages/platform-android); the iOS probe is owned by refactor(daemon): own Apple runner session observation behind a semantic port #2332 (this issue depends on refactor(daemon): own Apple runner session observation behind a semantic port #2332 for the shared file src/platform-runtime-open-target.ts).
• If the neutral surface stays a root module, its remaining daemon consumers are classified daemon-policy-essential in the R74 inventory with the plan-construction rationale; if it moves, the move is a pure seam change with no behavior change.

Observable completion conditions

• The two R74 inventory edges above are reclassified or removed.
• resolveAndroidPackageForOpen / inferAndroidPackageAfterOpen have no production importer outside their owning seam.
• open prepare and selector dispatch behave identically (existing behavior tests).
• Planted violation: a daemon import of the platform-mechanics symbols is red.
• pnpm check:layering and pnpm check:affected --run pass.

Dependencies

Blocked by: #2332 (shared file src/platform-runtime-open-target.ts hosts the probe #2332 relocates).