fix(ime): exitFloatingMode used LinearLayout.LayoutParams on the docked root (#43)

[willwade]

Fixes #43.

Root cause

DasherImeService.exitFloatingMode() (line 248) set LinearLayout.LayoutParams on the docked root. But the docked root's parent is the IME window's FrameLayout-based DecorView — the next layout pass (Choreographer.doFrame → DecorView.onMeasure → FrameLayout.onMeasure) tries to cast the child's LayoutParams to FrameLayout.LayoutParams and crashes.

This bug was already found and fixed twice — the code comment at line 115 documents the original fix, and enterFloatingMode (the Float shrink, line 209) also correctly uses FrameLayout.LayoutParams. But the exit path (Dock button → return to full keyboard) was the one remaining site with the wrong type. Every Float → Dock transition armed the crash.

The crash path from the user report

Float tapped → floating overlay created, docked root shrinks (FrameLayout.LayoutParams ✓)
Dock tapped → exitFloatingMode → docked root restored to full size (LinearLayout.LayoutParams ✗)
Next frame → Choreographer.doFrame → ViewRootImpl.performTraversals
           → DecorView.onMeasure → FrameLayout.onMeasure(208)
           → (FrameLayout.LayoutParams) child.getLayoutParams() → CRASH

Fix

One line: LinearLayout.LayoutParams → android.widget.FrameLayout.LayoutParams at line 248, with a comment matching the existing two correct sites.

Testing

Manual verification needed: enter Float mode, tap Dock, type — no crash. The crash was $exception_handled: true (caught by the handler, not a hard crash) but still breaks the keyboard.

Companion: #44 (ProGuard mapping upload — needed for readable stacks on the next crash).

[willwade]

Review-loop summary (1 pass, 8/10 — gate met)

Verified correct: the one-line fix closes the last wrong-type path — all three layoutParams assignments on the docked root now use FrameLayout.LayoutParams (verified exhaustive against every layoutParams and addView in the file). setLayoutParams performs no type conversion — the wrong type survives until FrameLayout.onMeasure casts it. Mechanism matches the crash exactly.

Fixes applied from the review (5b71871):

• setDockedHeight() helper — single site for docked root LayoutParams; the same comment was copy-pasted three times and the bug had already recurred once after being "fixed twice." Now structurally impossible.
• imeHeightPx() — shared height formula (was duplicated; drift would give different dock heights after Float → Dock).
• Drag handler's updateViewLayout wrapped in try/catch — a queued ACTION_MOVE after onDestroy removes the overlay → IllegalArgumentException (same lifecycle-race family).

Noted as follow-ups (not blocking):

• Config change while floating: onCreateInputView would create a second engine + dead Float button. Worth a separate issue.
• No automated regression test for the LayoutParams type — deterministic but requires Robolectric or view-construction extraction. Manual repro (Float → Dock → rotate) documented in the PR body.