epic(ui): Fluid morphing — evolve QueryaMotion (post-0.4.11 shell)

[ZhuchkaTriplesix]

Context

QueryaMotion foundation shipped in 0.4.4. After shell UX #339 (on dev / planned 0.4.11), tokens cover toast/tab strip/dialogs/trees, but major shell transitions are still hard-cuts.

Design / plan: Obsidian 06 — Планирование/Fluid morphing и QueryaMotion (based on dev post-#339).

Goal

Make the desktop shell feel continuous (morphing), without rewriting shadcn or blocking the 0.4.11 release.

Prefer: land after 0.4.11 packaging, or small non-blocking PRs on dev if release is delayed.

Workstreams

Phase A — Primitives (lib/core/motion/)

• QueryaFadeSlide (enter/exit + offset)
• QueryaHoverSurface (unified hover)
• QueryaSwitchingBody (preserve mounted children like CrossFadeStack)
• QueryaStagger (first-paint only, capped)
• Widget tests + honor Full/Reduced/Off + OS disableAnimations

Phase B — Shell morphing

• Empty hero ↔ connected workspace (workspace_panel / workspace_empty_hero)
• Tab strip sliding indicator (querya_tab_strip)
• Hero quick-start ↔ recent list transition
• Results idle → running → grid/error (no per-row scroll animation)
• Dialog/dropdown exit curves + fade-slide enter
• Theme animation tied to motion level
• Split-handle focus / sidebar drag-end settle (not mid-drag)

Phase C — Guardrails

• Update docs/perf-baseline.md scenarios @ 120 Hz
• Review rule: no magic UI Duration for animations

Non-goals

• Animating virtualized grid rows on scroll
• Replacing shadcn / expanding third_party for motion
• Rust core (parallel research track)

Depends on

• Shell chrome from epic(ui): harden desktop shell UX, accessibility, and visual consistency #339 (already on dev)
• Preferably released baseline 0.4.11 so morphing ships as a focused follow-up

[ZhuchkaTriplesix]

Does not block #341. Prefer after 0.4.11 ships.

[ZhuchkaTriplesix]

Obsidian section created: 12 — Fluid Morphing

• Hub + full research (WWDC requirements, springs, Flutter packages, Rust)
• Requirements: Responsive / Interruptible / Redirectable
• Querya conclusions + updated plan (springs, not duration-only)

Vault path: Querya/12 — Fluid Morphing/Fluid Morphing.md

[ZhuchkaTriplesix]

Progress (branch issue/342-fluid-motion-primitives)

Phase 2 primitives landed locally:

• QueryaSpring + QueryaSpringController (interruptible retarget / velocity handoff; Full-only)
• QueryaFadeSlide, QueryaHoverSurface, QueryaSwitchingBody, QueryaStagger
• Wired QueryaSwitchingBody into workspace_panel (empty ↔ connected morph, keep-alive cache)
• Tests green: test/core/motion/ (+ workspace layout)

Next on this epic: tab strip sliding indicator, dialog interruptible open/close, split settle, stagger on recent list.