docs: replace ampersand headings for stable Mintlify anchors

Per docs/CLAUDE.md, Mintlify anchor generation is brittle for headings
that contain em dashes, apostrophes, and ampersands. Normalize 9 H2
headings across docs/date-time.md, docs/pi.md, docs/platforms/{index,
macos, mac/webchat, mac/peekaboo}.md, docs/nodes/{images,audio}.md, and
docs/reference/AGENTS.default.md from `X & Y` to `X and Y` so anchors
do not collapse on entity decoding. Verified no inbound anchor references
to the renamed sections in the docs tree.

docs/platforms/index.md

@@ -22,7 +22,7 @@ Native companion apps for Windows are also planned; the Gateway is recommended v
 - Windows: [Windows](/platforms/windows)
 - Linux: [Linux](/platforms/linux)
 
-## VPS & hosting
+## VPS and hosting
 
 - VPS hub: [VPS hosting](/vps)
 - Fly.io: [Fly.io](/install/fly)

docs/platforms/mac/peekaboo.md

@@ -65,7 +65,7 @@ socket path is in use. You can override with:
 export PEEKABOO_BRIDGE_SOCKET=/path/to/bridge.sock
 ```
 
-## Security & permissions
+## Security and permissions
 
 - The bridge validates **caller code signatures**; an allowlist of TeamIDs is
   enforced (Peekaboo host TeamID + OpenClaw app TeamID).

docs/platforms/mac/webchat.md

@@ -13,7 +13,7 @@ agent (with a session switcher for other sessions).
 - **Remote mode**: forwards the Gateway control port over SSH and uses that
   tunnel as the data plane.
 
-## Launch & debugging
+## Launch and debugging
 
 - Manual: Lobster menu → “Open Chat”.
 - Auto‑open for testing:

docs/platforms/macos.md

@@ -162,7 +162,7 @@ If `openclaw doctor` detects state under:
 
 it will warn and recommend moving back to a local path.
 
-## Build & dev workflow (native)
+## Build and dev workflow (native)
 
 - `cd apps/macos && swift build`
 - `swift run OpenClaw` (or Xcode)