fix(newos4): grep, head and tail take every path argument (v4.6.67)

Packet 1's multi-path ask was only honoured by wc in v4.6.58 — grep read only
args[ai+1] and head/tail only positional[0], so `grep x a b` searched `a`, printed
one file's hits, and exited 0. Same silent drop, three more commands.

- grep: loops every path; multiple files print `file:line: text`, `-c` prints one
  count per file, missing files are reported per file and excluded from the summary
  count; single-file output unchanged
- head: every path, `==> file <==` header when more than one; `head f 40` still works
- tail: every path with headers; a numeric second positional is still the legacy
  `tail <file> <count>`; `-f` warns and follows only the first file instead of
  printing all of them and claiming otherwise

Verified live on v4.6.67:
grep "bug_id" a b        -> a:2 + b:3 + "2 match(es) in 2 file(s)"
grep -c "alpha" a b      -> one count per file
grep "alpha" a missing   -> hits from a, per-file error, "in 1 file(s)"
head -n 1 a b            -> header + first line for each
tail -n 1 a b            -> header + last line for each
tail a 2                 -> legacy count still honoured
tail -f a b              -> warns, follows a only

1 files changed, 1 insertions, 1 deletions

diff --git a/modules/core/module-loader.js b/modules/core/module-loader.js
index e3905ee..badaeed 100644
--- a/modules/core/module-loader.js
+++ b/modules/core/module-loader.js
@@ -4,7 +4,7 @@
     // Core module bundle loaded synchronously in main.html.
     // This loader only handles version cache-busting, splash, terminal init, and optional ext modules.
 
-    const LATEST_VER = 'v4.6.65';
+    const LATEST_VER = 'v4.6.67';
     const CACHE = '?v=' + LATEST_VER;
     const stored = localStorage.getItem('webx11_cache_ver');
     if (stored !== LATEST_VER) {