invert dependency: internal no longer imports internal/tui

Introduce internal/runtime as a neutral contract package that both the
core engine (internal) and the TUI layer (internal/tui) depend on.

- internal/runtime: defines TraceStarter, StreamSource, EventSink,
  LiveTrieSource, SnapshotSource, ProbeManager, RuntimePublisher,
  RuntimeState, TraceRuntimeBindings, and all context key/helper
  functions (RuntimeBindingsFromContext, RuntimePublisherFromContext,
  ContextWithRuntimeBindings, ContextWithTraceFilters,
  TraceFiltersFromContext). These were previously defined in
  internal/tui, forcing the core package to import the TUI layer.

- internal/streamrow: add RingBuffer (moved from internal/tui/eventstream)
  so the core tracing engine can use the ring buffer without importing
  the TUI layer.

- internal/tui/eventstream/ringbuffer.go: change to a thin re-export of
  streamrow.RingBuffer via a type alias, preserving the existing API for
  all callers within the TUI layer.

- internal/tui/tui.go: replace locally-defined interface declarations
  (TraceStarter, SnapshotSource, ProbeManager, RuntimePublisher,
  RuntimeState, TraceRuntimeBindings) with type aliases from
  internal/runtime. Delegate all context helper functions to runtime.

- internal/ior.go, internal/ior_bpfsetup.go: remove imports of
  internal/tui and internal/tui/eventstream; use internal/runtime and
  internal/streamrow instead. Add SetTUIRunners injection point so the
  concrete TUI runner functions are wired in by cmd/ior/main.go.

- cmd/ior/main.go: call internal.SetTUIRunners with the concrete TUI
  runner functions before internal.Run, completing the wiring without
  creating a cycle.

- Test files (internal/ior_mode_test.go, internal/bench_pipeline_test.go):
  updated to use runtime.* and streamrow.* types in place of tui.* and
  eventstream.* types.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/internal/bench_pipeline_test.go b/internal/bench_pipeline_test.go
index b520c9c..7967e3a 100644
--- a/internal/bench_pipeline_test.go
+++ b/internal/bench_pipeline_test.go
@@ -11,7 +11,7 @@ import (
 	"ior/internal/flamegraph"
 	"ior/internal/parquet"
 	"ior/internal/statsengine"
-	"ior/internal/tui/eventstream"
+	"ior/internal/streamrow"
 )
 
 const (
@@ -198,8 +198,8 @@ func benchmarkPipelineTUIParquet(b *testing.B, mix benchutil.EventMix, events, n
 		preseedBenchComms(el, numThreads)
 
 		engine := statsengine.NewEngine(64)
-		streamBuf := eventstream.NewRingBuffer()
-		streamSeq := eventstream.NewSequencer(0)
+		streamBuf := streamrow.NewRingBuffer()
+		streamSeq := streamrow.NewSequencer(0)
 		liveTrie := flamegraph.NewLiveTrie([]string{"comm", "tracepoint", "path"}, "count")
 
 		recorder := parquet.NewRecorder(parquet.RecorderConfig{})
@@ -212,7 +212,7 @@ func benchmarkPipelineTUIParquet(b *testing.B, mix benchutil.EventMix, events, n
 
 		var recordErr error
 		el.printCb = func(ep *event.Pair) {
-			row := eventstream.NewStreamEvent(streamSeq.Next(), ep)
+			row := streamrow.New(streamSeq.Next(), ep)
 			engine.Ingest(ep)
 			streamBuf.Push(row)
 			if recordErr == nil {