chore(audit): triage webapp/tui/voxtype install-remove pairs

Pillar 3 Phase B, batch 3 — Batch A of the unused? clusters.

Deleted two dead webapp URI handlers:
- `nomarchy-webapp-handler-hey`
- `nomarchy-webapp-handler-zoom`

Neither was registered as a MimeType handler anywhere — a grep across
`*.desktop` files in `core/`, `features/`, `themes/`, `installer/`, and
`hosts/` returned zero matches. Without a `.desktop` registration the
system never routes `mailto:`/`zoom:`/`zoomus:` URIs to them, so the
handlers were unreachable code.

Kept the six remaining install/remove pairs (they're real CLI tools, just
unwired into any menu) and surfaced them in `SKILL.md` "Common Tasks" so
AI assistants can discover them on user request and the audit tags them
`kept`:
- Custom App Launchers: webapp-{install,remove,remove-all},
  tui-{install,remove,remove-all}
- Voice dictation: voxtype-{install,remove,status}

Menu-wiring these (e.g. a "Setup → Apps" submenu in nomarchy-menu) is a
separate Pillar 6 onboarding job, not scoped here.

Regenerated `docs/SCRIPTS.md` — script count 166 → 164, `unused?` 21 → 13.
Logged in `docs/ROADMAP.md` Shipped.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

features/scripts/utils/nomarchy-webapp-handler-hey

@@ -1,12 +0,0 @@
-#!/bin/bash
-set -e
-url="$1"
-web_url="https://app.hey.com"
-
-# Handle mailto: URLs
-if [[ $url =~ ^mailto: ]]; then
-  email=$(echo "$url" | sed 's/mailto://')
-  web_url="https://app.hey.com/messages/new?to=$email"
-fi
-
-exec nomarchy-launch-webapp "$web_url"

features/scripts/utils/nomarchy-webapp-handler-zoom

@@ -1,21 +0,0 @@
-#!/bin/bash
-set -e
-
-url="$1"
-web_url="https://app.zoom.us/wc/home"
-
-if [[ $url =~ ^zoom(mtg|us):// ]]; then
-  confno=$(echo "$url" | sed -n 's/.*[?&]confno=\([^&]*\).*/\1/p')
-
-  if [[ -n $confno ]]; then
-    pwd=$(echo "$url" | sed -n 's/.*[?&]pwd=\([^&]*\).*/\1/p')
-
-    if [[ -n $pwd ]]; then
-      web_url="https://app.zoom.us/wc/join/$confno?pwd=$pwd"
-    else
-      web_url="https://app.zoom.us/wc/join/$confno"
-    fi
-  fi
-fi
-
-exec nomarchy-launch-webapp "$web_url"