feat: LTL operators, sampling, and default generators (#17)

* feat(ltl): add Now/Next/Eventually/Implies/Or/And/Not formulas

Replace the fold-with-latch evaluator with a residual-formula reducer.
Each Observe() instantiates a fresh obligation from the root (stripping
an outer Always), reduces each pending obligation against current state,
latches Violated on first failure, and surfaces Pending verdicts for
deferred obligations. Existing Always/Pure/Thunk tests continue to pass.

* feat(ltl): support relative duration for eventually().within()

* feat(proto): add Swipe, PressKey, RecentLogs RPCs

* feat(verifier,runner): formula handles, new action kinds, rich state

- verifier: add formula-spec registry; bindNow/bindNext/bindEventually with
  chainable .implies/.or/.and/.not and .within(n,unit) on eventually; bindFrom
  for uniform sampling. bindAlways keeps accepting plain predicates.
- verifier: store lastTree, lastAction, step time, logs, exceptions on the
  Verifier; SnapshotInput replaces the (snapshots, tree) pair. stateObject now
  produces state.lastAction/time/logs/exceptions matching the TS State type.
- verifier: make taps/swipes/waitOnce/pressKey built-in generators actually
  fire; taps picks a clickable, enabled element from the last hierarchy.
- agent: add exceptions field to Message wire format.
- driver: add Swipe/PressKey/RecentLogs to Driver interface; wire maestro
  client and mock driver. LogEntry exposed for runner consumption.
- runner: apply Swipe/PressKey/Wait actions; collect logcat and exceptions;
  pass lastAction and step time into PushSnapshot.

* feat(spec-api): LTL operators, new actions, richer State

- ltl.ts exports now/next/eventually; always overload accepts a Formula
- types.ts: Formula gains implies/or/and/not; EventuallyFormula adds .within;
  State gains lastAction/time/logs/exceptions; Swipe/PressKey/Wait action types
- actions.ts: Swipe/PressKey/Wait/from constructors; waitOnce + pressKey
  default generators
- tests exercise the chaining, sampling, and new actions through a recorded
  fake runtime

* feat(sidecar): add swipe, pressKey, recentLogs RPC handlers

* feat(sdk-android): capture uncaught exceptions

Install a default uncaught handler on Uatu.start, chained with any
existing handler so Android's crash reporter still runs. Expose
Uatu.reportError for callers to forward caught throwables. A bounded
circular buffer (default 50) drains into each STATE message's new
exceptions field. Protocol.kt serializes/deserializes the field,
matching the Go wire format added to internal/agent/protocol.go.

* feat(spec-api): add @uatu/spec/defaults/properties bundle

* feat(sample-app): exercise new LTL operators + defaults

spec.ts now imports eventually/next/now/from from @uatu/spec and
noUncaughtExceptions from @uatu/spec/defaults/properties. It declares
three properties that exercise the new surface:

- accountCountNonNegative: plain always() safety
- addAccountAdvances: always(now(x).implies(next(y)))
- eventuallyLoggedIn: eventually(p).within(30, "seconds")
- noUncaughtExceptions: imported default

The weighted actions root uses from() for random phone/name sampling
and entries for taps/swipes/waitOnce/pressKey built-ins.

SampleApplication gains a debug hook gated on the system property
uatu.inject_error so the e2e run can synthesize an Uatu.reportError and
verify noUncaughtExceptions violates.

cmd/uatu/test_run.go adds a subpath alias so specs importing
"@uatu/spec/defaults/properties" resolve against the in-tree source
when running from the uatu checkout. The spec-integration tests swap
the old click-counter fixtures for the new login hierarchy.

* feat(trace): record swipe/key/wait details + exceptions

trace.Step gains an Exceptions array so the trace captures the
class/message/stackTrace for each SDK-reported throwable in a step.
trace.Action gains FromX/FromY/ToX/ToY/Key/DurationMillis so the full
payload of Swipe/PressKey/Wait actions is visible in trace.jsonl.

sample-app's debug error hook now gates on ApplicationInfo.DEBUGGABLE
instead of a system property (adb setprop fails on non-rooted
emulators).

internal/driver/mock/mock.go

@@ -16,8 +16,11 @@ const (
 	ActionTap         ActionKind = "tap"
 	ActionTapSelector ActionKind = "tap_selector"
 	ActionInputText   ActionKind = "input_text"
+	ActionSwipe       ActionKind = "swipe"
+	ActionPressKey    ActionKind = "press_key"
 	ActionHierarchy   ActionKind = "hierarchy"
 	ActionScreenshot  ActionKind = "screenshot"
+	ActionRecentLogs  ActionKind = "recent_logs"
 	ActionWaitForIdle ActionKind = "wait_for_idle"
 	ActionHealth      ActionKind = "health"
 )
@@ -28,8 +31,14 @@ type Action struct {
 	LauncherActivity string
 	ClearState       bool
 	X, Y             int
+	FromX, FromY     int
+	ToX, ToY         int
+	Duration         time.Duration
 	Selector         string
 	Text             string
+	Key              string
+	LogLevel         string
+	LogSince         time.Time
 	Idle             time.Duration
 }
 
@@ -43,6 +52,7 @@ type Driver struct {
 	HierarchyJSON string
 	ImageData     driver.Image
 	HealthInfo    driver.Health
+	LogEntries    []driver.LogEntry
 	Failures      map[ActionKind]error
 }
 
@@ -117,6 +127,39 @@ func (d *Driver) InputText(ctx context.Context, text string) error {
 	return nil
 }
 
+func (d *Driver) Swipe(ctx context.Context, fromX, fromY, toX, toY int, duration time.Duration) error {
+	if err := d.failure(ActionSwipe); err != nil {
+		return err
+	}
+	d.record(Action{
+		Kind:     ActionSwipe,
+		FromX:    fromX,
+		FromY:    fromY,
+		ToX:      toX,
+		ToY:      toY,
+		Duration: duration,
+	})
+	return nil
+}
+
+func (d *Driver) PressKey(ctx context.Context, key string) error {
+	if err := d.failure(ActionPressKey); err != nil {
+		return err
+	}
+	d.record(Action{Kind: ActionPressKey, Key: key})
+	return nil
+}
+
+func (d *Driver) RecentLogs(ctx context.Context, since time.Time, minLevel string) ([]driver.LogEntry, error) {
+	if err := d.failure(ActionRecentLogs); err != nil {
+		return nil, err
+	}
+	d.record(Action{Kind: ActionRecentLogs, LogSince: since, LogLevel: minLevel})
+	d.mutex.Lock()
+	defer d.mutex.Unlock()
+	return append([]driver.LogEntry(nil), d.LogEntries...), nil
+}
+
 func (d *Driver) Hierarchy(ctx context.Context) (string, error) {
 	if err := d.failure(ActionHierarchy); err != nil {
 		return "", err