feat(mdns): añadir resolver genérico + helpers de shell

- bin/resolve: hostname -> IP con orden mDNS (LAN) -> Tailscale -> caché.
  Reutilizable en cualquier comando (ping, curl, kubectl, nc).
- bin/ssh-mdns-proxy: arreglar shebang (#\! -> #!) que hacía fallar
  declare -A al caer en sh; y reemplazar getent (inexistente en Termux)
  por python socket.gethostbyname, con detección para portabilidad.
- config/bashrc.snippet: añadir aliases r/pingr/sshr/curlr. sshr usa
  HostKeyAlias para que SSH-por-IP no falle verificación de known_hosts.
- docs/03-ssh-mdns-tailscale.md: sección nueva sobre resolve + gotchas
  (getent ausente, shebang bash-only, mDNS no cruza redes).
- install.sh: incluir resolve en la lista de scripts a instalar.
- README.md: nueva fila en la tabla de componentes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -43,6 +43,7 @@ bash install.sh --dry-run
 | `mdns-publish.py` | `~/.local/bin/` | Publish this device as `movil.local` (needs `zeroconf`) |
 | `ssh-mdns-proxy` | `~/.local/bin/` | SSH ProxyCommand: mDNS → Tailscale |
 | `ssh-fallback` | `~/.local/bin/` | SSH ProxyCommand: Tailscale → LAN fallback |
+| `resolve` | `~/.local/bin/` | Generic host resolver: mDNS → Tailscale → cache (for any command) |
 | `settings.json` | `~/.claude/` | Disables auto-updater |
 
 ## Usage

bin/resolve

@@ -0,0 +1,47 @@
+#!/data/data/com.termux/files/usr/bin/bash
+# resolve: hostname -> IP con fallback mDNS (LAN) -> Tailscale DNS -> cache
+# Uso:  resolve <hostname>[.local|.tailnet]
+# Ej:   resolve lenovo                  # -> 100.69.236.16
+#       ping $(resolve hp62a)
+#       curl "http://$(resolve dell):8080"
+set -e
+HOST="${1:-}"
+[[ -z "$HOST" ]] && { echo "Uso: resolve <hostname>" >&2; exit 1; }
+
+CACHE="$HOME/.ssh/resolve-cache"
+TAILSCALE_DOMAIN="${TAILSCALE_DOMAIN:-tailb0bb74.ts.net}"
+MDNS_TIMEOUT="${MDNS_TIMEOUT:-1}"
+
+QUERY="${HOST%.local}"
+QUERY="${QUERY%.${TAILSCALE_DOMAIN}}"
+
+declare -A ALIASES=(
+    [dell]="dell-latitude3400"
+    [lenovo]="lenovo-ideapad"
+)
+[[ -n "${ALIASES[$QUERY]:-}" ]] && QUERY="${ALIASES[$QUERY]}"
+
+# 1. mDNS multicast (LAN)
+IP=$("$HOME/.local/bin/mdns-resolve" "${QUERY}.local" "$MDNS_TIMEOUT" 2>/dev/null || true)
+
+# 2. Tailscale MagicDNS (remoto)
+if [[ -z "$IP" ]]; then
+    IP=$(python -c "import socket; print(socket.gethostbyname('${QUERY}.${TAILSCALE_DOMAIN}'))" 2>/dev/null || true)
+fi
+
+# 3. Cache
+if [[ -z "$IP" && -f "$CACHE" ]]; then
+    IP=$(grep "^${QUERY} " "$CACHE" 2>/dev/null | awk '{print $2}')
+fi
+
+if [[ -z "$IP" ]]; then
+    echo "Error: no se resuelve '${HOST}'" >&2
+    exit 1
+fi
+
+mkdir -p "$(dirname "$CACHE")"
+grep -v "^${QUERY} " "$CACHE" > "${CACHE}.tmp" 2>/dev/null || true
+echo "${QUERY} ${IP}" >> "${CACHE}.tmp"
+mv "${CACHE}.tmp" "$CACHE"
+
+echo "$IP"

bin/ssh-mdns-proxy

@@ -24,9 +24,13 @@ SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
 # 1. mDNS resolution
 IP=$("$SCRIPT_DIR/mdns-resolve" "${QUERY}.local" 2 2>/dev/null)
 
-# 2. Fallback: Tailscale DNS
+# 2. Fallback: Tailscale DNS (Termux carece de getent, usar python si esta disponible)
 if [[ -z "$IP" ]]; then
-    IP=$(getent hosts "${QUERY}.${TAILSCALE_DOMAIN}" 2>/dev/null | awk '{print $1}')
+    if command -v getent >/dev/null 2>&1; then
+        IP=$(getent hosts "${QUERY}.${TAILSCALE_DOMAIN}" 2>/dev/null | awk '{print $1}')
+    else
+        IP=$(python -c "import socket; print(socket.gethostbyname('${QUERY}.${TAILSCALE_DOMAIN}'))" 2>/dev/null)
+    fi
 fi
 
 # 3. Fallback: cached IP

config/bashrc.snippet

@@ -27,6 +27,21 @@ alias mdns-status='pgrep -af mdns-publish || echo "mDNS publisher is not running
 alias mdns-restart='pkill -f mdns-publish; sleep 1; nohup python ~/.local/bin/mdns-publish.py >>~/.cache/mdns.log 2>&1 & disown && echo "mDNS restarted"'
 alias mdns-stop='pkill -f mdns-publish && echo "mDNS stopped"'
 
+# === Generic host resolver (resolve: mDNS -> Tailscale -> cache) ===
+# Works in any command:  ping $(resolve lenovo)  /  curl "http://$(resolve hp62a)"
+alias r='resolve'
+pingr()   { ping -c 3 "$(resolve "$1")"; }
+curlr()   { local h="$1"; shift; curl "$@" "http://$(resolve "$h")"; }
+# HostKeyAlias reuses the known_hosts entry for the Tailscale FQDN
+# so SSH-by-IP does not fail host-key verification.
+sshr()    {
+    local h="$1"; shift
+    local canonical="$h"
+    case "$h" in dell) canonical="dell-latitude3400";; lenovo) canonical="lenovo-ideapad";; esac
+    ssh -o "HostKeyAlias=${canonical}.${TAILSCALE_DOMAIN:-tailb0bb74.ts.net}" \
+        "YOUR_USER@$(resolve "$h")" "$@"
+}
+
 # === Optional: auto-start samba + mDNS on shell login ===
 # Uncomment the block below if you want services up automatically.
 # Failures are logged (NOT silenced) — silent failures after a tar restore are the worst class of bug.

docs/03-ssh-mdns-tailscale.md

@@ -10,6 +10,7 @@ Termux's Bionic libc does **not** resolve `.local` names. This repo ships small
 | `mdns-publish.py` | Publish this device on the LAN as `movil.local` (or whatever you choose) using `zeroconf`. |
 | `ssh-mdns-proxy` | SSH `ProxyCommand` that tries mDNS first, then Tailscale DNS. Used from `~/.ssh/config`. |
 | `ssh-fallback` | Lower-level fallback: tries Tailscale, then LAN. Useful when Tailscale is flaky. |
+| `resolve` | Generic resolver for **any** command (ping, curl, kubectl…). Same order: mDNS → Tailscale → cache. |
 
 ## SSH config
 
@@ -58,3 +59,41 @@ When you list hosts in `~/.ssh/config`, prefer:
 2. `<host>.YOUR-TAILNET.ts.net` for off-LAN
 
 Never hardcode IPs — they rotate.
+
+## Generic resolver (`resolve`) for any command
+
+`ssh-mdns-proxy` only helps SSH. For everything else — `ping`, `curl`, `kubectl`, `nc` — use `resolve`. It applies the same lookup order and updates the cache:
+
+```bash
+resolve lenovo                       # -> 100.69.236.16
+ping   $(resolve hp62a)
+curl   "http://$(resolve dell):8080"
+```
+
+Environment knobs:
+
+- `TAILSCALE_DOMAIN` — defaults to `tailb0bb74.ts.net`. Set to your own tailnet.
+- `MDNS_TIMEOUT` — seconds for multicast (`1` by default, low so remote calls stay snappy).
+
+Short aliases and helper functions to drop into `~/.bashrc` (see `config/bashrc.snippet`):
+
+```bash
+alias r='resolve'
+pingr()   { ping -c 3 "$(resolve "$1")"; }
+sshr()    {
+    local h="$1"; shift
+    local canonical="$h"
+    case "$h" in dell) canonical="dell-latitude3400";; lenovo) canonical="lenovo-ideapad";; esac
+    ssh -o "HostKeyAlias=${canonical}.${TAILSCALE_DOMAIN:-tailb0bb74.ts.net}" \
+        "YOUR_USER@$(resolve "$h")" "$@"
+}
+curlr()   { local h="$1"; shift; curl "$@" "http://$(resolve "$h")"; }
+```
+
+`HostKeyAlias` in `sshr` is important: since we connect by IP, SSH would fail host-key verification otherwise. Aliasing back to the canonical Tailscale FQDN reuses the `known_hosts` entry you already trust.
+
+## Gotchas found the hard way
+
+- **`getent` doesn't exist on Termux.** Any script that shells out to it for DNS will silently fail. `resolve` and `ssh-mdns-proxy` fall back to `python -c "import socket; socket.gethostbyname(...)"` — that's the portable way on Bionic.
+- **Shebang matters.** `#!/data/data/com.termux/files/usr/bin/bash` is required for `declare -A` (associative arrays). A stray backslash (`#\!`) makes the kernel fall through to `sh`, which silently rejects bash-only syntax with `Syntax error: "(" unexpected`.
+- **mDNS off-LAN is a no-op.** Multicast (224.0.0.251) does not cross networks. Over mobile data the Tailscale fallback is the only path that works.

install.sh

@@ -59,7 +59,7 @@ fi
 # 4. Install scripts
 step 4 "Installing scripts to $BIN_DIR..."
 run mkdir -p "$BIN_DIR"
-for script in clauded claude-check-env claude-update mdns-resolve mdns-publish.py ssh-mdns-proxy ssh-fallback; do
+for script in clauded claude-check-env claude-update mdns-resolve mdns-publish.py ssh-mdns-proxy ssh-fallback resolve; do
     run cp "$SCRIPT_DIR/bin/$script" "$BIN_DIR/$script"
     run chmod +x "$BIN_DIR/$script"
 done