homelab v0.8.2: fix memory recall truncating multibyte UTF-8 mid-character

emo's Claude Code sessions hit "UserPromptSubmit hook error" on almost every
prompt. Root cause: the homelab-memory-recall.py UserPromptSubmit hook runs
`homelab memory recall <prompt>` and strict-decodes its stdout. printMemories
truncated each memory's preview with a BYTE slice (c[:240]), which cuts through
the middle of a 2-byte Cyrillic character and emits invalid UTF-8 (a dangling
0xd0 lead byte). The hook's subprocess.run(text=True) then raised
UnicodeDecodeError — not caught by its `except (TimeoutExpired, OSError)` — so
the hook exited non-zero and Claude surfaced the error. It is Cyrillic-specific
(ASCII has no multibyte chars to split), so it bit emo (Bulgarian prompts) every
turn while English users almost never saw it.

Two-layer fix:
- cli: truncatePreview() now counts RUNES, not bytes, so the preview never
  splits a character. Regression test asserts valid UTF-8 on a long Cyrillic
  string. Fixes the root for every consumer of `memory recall` / `memory list`.
- hook: subprocess.run gains errors="replace" and the except is broadened to
  honor the script's own "best-effort, exit 0" contract — so a truncated or
  otherwise odd payload can never again surface as a hook error.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

scripts/workstation/claude-hooks/homelab-memory-recall.py

@@ -45,9 +45,15 @@ def main() -> None:
     try:
         res = subprocess.run(
             [homelab, "memory", "recall", prompt, "--limit", "5"],
-            capture_output=True, text=True, timeout=4, env=os.environ,
+            capture_output=True, text=True, errors="replace", timeout=4,
+            env=os.environ,
         )
-    except (subprocess.TimeoutExpired, OSError):
+    except Exception:
+        # Best-effort: ANY failure — timeout, OSError, or a UnicodeDecodeError on
+        # truncated multibyte (Cyrillic) output — must silently skip recall this
+        # turn, exactly like the MCP being unavailable. errors="replace" above
+        # also keeps a mid-rune-truncated payload from raising here at all. Never
+        # let this hook surface a "UserPromptSubmit hook error".
         return
 
     out = (res.stdout or "").strip()