Fix mempalace init hang on stdin in docker run -it

mempalace init has an interactive 'Mine this directory now? [Y/n]' prompt
at the end that --yes does not auto-answer in all paths (notably empty
or near-empty workspaces). The entrypoint redirected stdout/stderr to
/dev/null but left stdin connected to the TTY. When invoked from
'docker run -it' the process blocked forever on stdin with 0% CPU,
silently — the user's symptom of 'still hangs at Initializing MemPalace
for workspace'.

Fix: redirect stdin from /dev/null too. EOF on stdin makes the prompt
fall through to its default (skip), and the process exits cleanly.

Verified locally: fresh-container start now completes in 1.3 seconds
(vs hanging indefinitely).

entrypoint-user.sh

@@ -25,7 +25,12 @@ if command -v mempalace &>/dev/null && [ -d /workspace ]; then
   PALACE_DIR="${HOME}/.mempalace"
   if [ ! -d "$PALACE_DIR/palace" ]; then
     echo "Initializing MemPalace for workspace (non-interactive)..."
-    mempalace init --yes /workspace >/dev/null 2>&1 || true
+    # </dev/null: mempalace init has an interactive "Mine this directory
+    # now? [Y/n]" prompt that --yes does not auto-answer in all paths.
+    # Without redirected stdin, the process blocks here forever when run
+    # from `docker run -it` (the TTY keeps stdin open). EOF on stdin
+    # makes the prompt fall through to its default (skip).
+    mempalace init --yes /workspace </dev/null >/dev/null 2>&1 || true
   fi
 fi