Read controller batteries, stop the model guessing system facts

- Game controllers report battery through their kernel driver, not
  BlueZ: bluetooth.sh falls back to the power supply named after the
  device address.
- Asked for a VM's IP after a listing without one, the model made one up
  without calling a tool. The default system prompt now says facts about
  the user's computer, devices, accounts, mail, calendar or money come
  only from a tool, or it says it does not know.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

3 files changed, 39 insertions, 3 deletions

diff --git a/AGENTS.md b/AGENTS.md
index 9542840..395fed6 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -369,6 +369,30 @@ file: the model fills parameters but cannot reach `mailctl tag` or
   confirmation before acting for exactly this reason.
 - These tools speak personal data (mail subjects, amounts) out loud.
 
+### Bluetooth and VM tools, live test (2026-09-26)
+
+`bluetooth` (bluetoothctl show/devices/info) and `vms` (virsh list,
+domstate, dominfo, domifaddr). Connecting devices and handling VMs are
+phase 2.
+
+- A game controller (DualSense) reports no `Battery Percentage` through
+  BlueZ; its kernel driver (hid-playstation, same for hid-sony and
+  hid-nintendo) exposes a power supply named after the device address.
+  `bluetooth.sh` reads `/sys/class/power_supply/*<mac>*/capacity` (and
+  `status` for charging) as a fallback. Live: "85 percento".
+- `virsh domifaddr` with the default lease source is empty for a bridged
+  guest; `--source arp` (then `agent`) has the address.
+- **The model invented a fact about the user's system.** After listing
+  the VMs, "what is buildsystem's IP?" got a made-up private address with
+  no tool call: the previous tool output had no IP and the model filled
+  the gap. Fix in the default system prompt: facts about the user's
+  computer, devices, accounts, mail, calendar or money come only from a
+  tool; if none can tell, say so, never guess. Same sequence after the
+  fix: it called `vms(name)` and read the real address. A custom
+  `system` in config.toml drops this rule unless it is copied in.
+- Whisper wrote "build system" as two words; the model mapped it to the
+  VM name `buildsystem` without help.
+
 ### Barge-in (2026-09-26)
 
 A button press cuts the current reply. A global `turn` counter goes up on
diff --git a/assistant.py b/assistant.py
index 3bd4b20..4ea8113 100644
--- a/assistant.py
+++ b/assistant.py
@@ -46,7 +46,10 @@ DEFAULTS = {
     "llm": "http://localhost:8181/v1",
     "system": ("You are a voice assistant. Your replies are spoken aloud, so answer "
                "briefly in plain sentences: no markdown, no lists, no emoji. "
-               "Reply in the language the user speaks, Italian or English."),
+               "Reply in the language the user speaks, Italian or English. "
+               "Facts about the user's computer, devices, accounts, mail, calendar "
+               "or money come only from a tool: call one, and if none can tell, "
+               "say you do not know. Never guess them."),
     "tool_rounds": 3,
     "whisper": {"model": "/data/voice-models/whisper/ggml-large-v3-turbo-q5_0.bin",
                 "device": 0, "port": 8182},
diff --git a/examples/tools/bluetooth.sh b/examples/tools/bluetooth.sh
index a3af0f9..c00c853 100755
--- a/examples/tools/bluetooth.sh
+++ b/examples/tools/bluetooth.sh
@@ -16,7 +16,7 @@
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #
 # bluetooth.sh: whether bluetooth is on, the connected devices with their
-# kind (BlueZ icon name) and battery when the device reports one, and the
+# kind (BlueZ icon name) and battery when it is known, and the
 # paired devices that are not connected. Only show, devices and info run
 # here: nothing connects, pairs or scans.
 
@@ -35,7 +35,16 @@ while read -r _ mac _; do
     if grep -q $'^\tConnected: yes' <<<"$info"; then
         kind=$(sed -n 's/^\tIcon: //p' <<<"$info")
         battery=$(sed -n 's/^\tBattery Percentage: .*(\([0-9]*\))$/\1/p' <<<"$info")
-        echo "connected: $alias (${kind:-unknown kind}${battery:+, battery $battery%})"
+        # Game controllers report it through their kernel driver instead
+        # (hid-playstation, hid-sony, hid-nintendo): a power supply named
+        # after the device's address.
+        charging=""
+        for supply in /sys/class/power_supply/*"${mac,,}"*; do
+            [ -r "$supply/capacity" ] || continue
+            battery=$(<"$supply/capacity")
+            [ "$(cat "$supply/status" 2>/dev/null)" = Charging ] && charging=", charging"
+        done
+        echo "connected: $alias (${kind:-unknown kind}${battery:+, battery $battery%}$charging)"
         connected=$((connected + 1))
     else
         others+=("$alias")