fix(command): add missing command handler wiring and lint fixes

Wire SetCommandHandler into ChannelInboundProcessor so slash commands
are intercepted before reaching the LLM. Also apply lint fixes across
command package (strconv.Itoa, comment formatting, unused code removal)
and remove obsolete tool-call-browser.vue component.

internal/command/formatter.go

@@ -11,13 +11,13 @@ import (
 //
 // Example output:
 //
-//	- mybot
-//	  Description: A helpful assistant
-//	  ID: abc123
+//   - mybot
+//     Description: A helpful assistant
+//     ID: abc123
 //
-//	- another
-//	  Description: Something else
-//	  ID: def456
+//   - another
+//     Description: Something else
+//     ID: def456
 func formatItems(items [][]kv) string {
 	if len(items) == 0 {
 		return ""
@@ -42,8 +42,8 @@ func formatItems(items [][]kv) string {
 //
 // Example output:
 //
-//	- ID: abc123
-//	- Name: mybot
+//   - ID: abc123
+//   - Name: mybot
 func formatKV(pairs []kv) string {
 	var b strings.Builder
 	for _, p := range pairs {