refactor: code organization cleanup (#35)

* chore: fix gitignore + decisions doc after web->inspect-ui rename

Update web/ references to inspect-ui/ in .gitignore and Makefile. Add
decisions.md tracking architectural decisions from code-org discussion.

* refactor: rename pkg/spec-api to pkg/spec

Aligns the directory name with the npm package name @sanderling/spec.
Updates Makefile, package.json directory field, and resolveSpecAPIPath.

* refactor(verifier): split bindings.go into types.go + bindings.go

Move shared public types (Action, ActionKind, LogEntry, Exception) to
types.go. bindings.go retains internal JS runtime wiring only.

* refactor(inspect): split runs.go into runs.go, runs_cache.go, runs_decode.go

runs.go: types (RunSummary, StepSummary, RunDetail, Run) and Scan.
runs_cache.go: Cache type, Open/Step/Detail methods, parseRun, scanSteps.
runs_decode.go: readMeta, tallyTrace, decodeStepSummary, validRunID.

* refactor: move android_env.go to internal/android/

Extracts Android device/AVD/adb logic into internal/android package.
Exports EnsureDevice, AdbReverse, AdbReverseRemove, EnvWithAndroidPlatformTools, AdbBinary.
Moves tests to internal/android/android_test.go. cmd/sanderling becomes a thin caller.

* refactor: extract test pipeline to internal/testrun/

runTestPipeline logic moves to testrun.Execute. buildDriver, resolveSpecAPIPath,
pickFreePort, and the progress logger move to internal/testrun/. cmd/sanderling/test_run.go
becomes a thin adapter. Tests follow their code.

* ci: update workflow paths after pkg/spec-api -> pkg/spec rename

internal/verifier/bindings.go

@@ -7,33 +7,6 @@ import (
 	"github.com/dop251/goja"
 )
 
-type ActionKind string
-
-const (
-	ActionKindTap       ActionKind = "Tap"
-	ActionKindInputText ActionKind = "InputText"
-	ActionKindSwipe     ActionKind = "Swipe"
-	ActionKindPressKey  ActionKind = "PressKey"
-	ActionKindWait      ActionKind = "Wait"
-)
-
-type Action struct {
-	Kind ActionKind
-	On   string
-	Text string
-	// X, Y hold the element center when the spec passed an ax element to
-	// Tap/InputText. Zero means the runner must resolve On against the
-	// current hierarchy.
-	X, Y int
-	// Swipe coordinates (raw px). Used only for ActionKindSwipe.
-	FromX, FromY int
-	ToX, ToY     int
-	// DurationMillis is the Swipe gesture duration or the Wait duration.
-	DurationMillis int
-	// Key is the logical key name for ActionKindPressKey.
-	Key string
-}
-
 type extractorState struct {
 	getter goja.Callable
 	handle *goja.Object