Fix bugs, remove duplication, and clean up code quality issues

- Log swallowed JSON unmarshal errors in stats and LSP handlers
- Fix debug log file handle leak in tmuxedit (return closer from initDebugLog)
- Check f.Close() errors on write paths in promptstore and tmuxedit
- Fix cacheGet TOCTOU race by using single write lock
- Fix readInput to use passed stdin reader instead of os.Stdin.Stat()
- Remove 45 'moved to' comment tombstones from lsp/handlers.go
- Deduplicate canonicalProvider wrappers (use llmutils.CanonicalProvider directly)
- Remove SetWindow side effect from stats.TakeSnapshot (pure read now)
- Move duplicated splitLines to textutil.SplitLinesBytes
- Collapse StatusSink.SetGlobal 10 params into GlobalStatus struct
- Simplify LRU touchLocked to in-place delete-and-append

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/internal/tmuxedit/history_test.go b/internal/tmuxedit/history_test.go
index b9d59d3..f6d6d7d 100644
--- a/internal/tmuxedit/history_test.go
+++ b/internal/tmuxedit/history_test.go
@@ -6,6 +6,8 @@ import (
 	"path/filepath"
 	"testing"
 	"time"
+
+	"codeberg.org/snonux/hexai/internal/textutil"
 )
 
 func TestAppendHistory(t *testing.T) {
@@ -164,7 +166,7 @@ func TestSplitLines(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got := splitLines([]byte(tt.input))
+			got := textutil.SplitLinesBytes([]byte(tt.input))
 			gotStr := make([]string, len(got))
 			for i, b := range got {
 				gotStr[i] = string(b)