fix(tools): Use ANNOTATIONS_CREATE for swap_pane

why: ANNOTATIONS_MUTATING advertises idempotentHint=True, but
`swap_pane(A, B)` is a toggle — calling it twice swaps the panes
back to their original positions, so repeated invocations do NOT
converge on a single state. Per the MCP annotation semantics
defined in src/libtmux_mcp/_utils.py (L55-66), non-idempotent
operations belong in ANNOTATIONS_CREATE (idempotentHint=False).
This matches the precedent already established on this branch
for send_keys, paste_text, and (commit 0df675f) pipe_pane.

what:
- Switch swap_pane registration from ANNOTATIONS_MUTATING to
  ANNOTATIONS_CREATE in pane_tools.register(). Tag remains
  TAG_MUTATING.

Author: tony

src/libtmux_mcp/tools/pane_tools.py

@@ -1274,7 +1274,7 @@ def register(mcp: FastMCP) -> None:
     mcp.tool(
         title="Select Pane", annotations=ANNOTATIONS_MUTATING, tags={TAG_MUTATING}
     )(select_pane)
-    mcp.tool(title="Swap Pane", annotations=ANNOTATIONS_MUTATING, tags={TAG_MUTATING})(
+    mcp.tool(title="Swap Pane", annotations=ANNOTATIONS_CREATE, tags={TAG_MUTATING})(
         swap_pane
     )
     mcp.tool(title="Pipe Pane", annotations=ANNOTATIONS_CREATE, tags={TAG_MUTATING})(