all: prepare 0.29.6 security updates

Updates #3579

cmd/hi/README.md

@@ -55,7 +55,7 @@ changing.
 | `--timeout`         | `120m`         | Total test timeout. Use the built-in flag — never wrap with bash `timeout`. |
 | `--postgres`        | `false`        | Use PostgreSQL instead of SQLite                                            |
 | `--failfast`        | `true`         | Stop on first test failure                                                  |
-| `--go-version`      | auto           | Detected from `go.mod` (currently 1.26.8)                                   |
+| `--go-version`      | auto           | Detected from `go.mod` (currently 1.27.3)                                   |
 | `--test-binary`     | unset          | Execute a precompiled integration test binary instead of running `go test`  |
 | `--clean-before`    | `true`         | Clean stale (stopped/exited) containers before starting                     |
 | `--clean-after`     | `true`         | Clean this run's containers after completion                                |

cmd/hi/run.go

@@ -118,7 +118,7 @@ func detectGoVersion() string {
 
 	content, err := os.ReadFile(goModPath)
 	if err != nil {
-		return "1.26.1"
+		return "1.27.3"
 	}
 
 	lines := splitLines(string(content))
@@ -133,7 +133,7 @@ func detectGoVersion() string {
 		}
 	}
 
-	return "1.26.1"
+	return "1.27.3"
 }
 
 // splitLines splits a string into lines without using [strings.Split].