feat: Add 'call' support to improve 2-way audio experience (#2486)

Draws significant inspiration (and direct styling) from
https://github.com/dermotduffy/advanced-camera-card/pull/2447 . Thank
you @Maudfer !

BREAKING CHANGE:

The microphone condition previously bundled two unrelated signals —
whether a two-way-audio session was connected and whether the microphone
was muted. Connection state is now its own dedicated call condition, and
microphone is reserved purely for mute state. Configs are upgraded
automatically (the card rewrites affected conditions under overrides,
elements, and automations). If you maintain config by hand, convert as
follows:

If you only used connected:

# Before
```yaml
condition: microphone
connected: true
```

# After
```yaml
condition: call
call: true
```
If you used both connected and muted — they must be split into two
conditions, since they no longer live together:

# Before
```yaml
condition: microphone
connected: true
muted: false
```

# After
```yaml
condition: and
conditions:
  - condition: call
    call: true
  - condition: microphone
    muted: false
```

docs/configuration/conditions.md

@@ -29,6 +29,21 @@ conditions:
 | `condition`  | Must be `and`.                                                                                                 |
 | `conditions` | A list of other conditions _all_ of which must evaluate `true` in order for this condition to evaluate `true`. |
 
+## `call`
+
+Matches based on whether a [two-way audio](../usage/2-way-audio.md) call is in progress.
+
+```yaml
+conditions:
+  - condition: call
+    # [...]
+```
+
+| Parameter   | Description                                                                                                                     |
+| ----------- | ------------------------------------------------------------------------------------------------------------------------------- |
+| `condition` | Must be `call`.                                                                                                                 |
+| `call`      | If `true` (the default) or `false`, the condition is satisfied when a two-way audio call is or is not in progress respectively. |
+
 ## `camera`
 
 Matches based on the selected camera. Does not match other cameras (whether
@@ -197,14 +212,10 @@ conditions:
     # [...]
 ```
 
-| Parameter   | Description                                                                                                            |
-| ----------- | ---------------------------------------------------------------------------------------------------------------------- |
-| `condition` | Must be `microphone`.                                                                                                  |
-| `connected` | Optional: If `true` or `false` the condition is satisfied if the microphone is connected or disconnected respectively. |
-| `muted`     | Optional: If `true` or `false` the condition is satisfied if the microphone is muted or unmuted respectively.          |
-
-When multiple parameters are specified they must all match for the condition to
-match.
+| Parameter   | Description                                                                                            |
+| ----------- | ------------------------------------------------------------------------------------------------------ |
+| `condition` | Must be `microphone`.                                                                                  |
+| `muted`     | If `true` or `false`, the condition is satisfied when the microphone is muted or unmuted respectively. |
 
 ## `not`
 
@@ -391,12 +402,14 @@ conditions:
 
 ```yaml
 conditions:
- - condition: camera
-   cameras:
-     - camera.office
+  - condition: call
+    call: true
+  - condition: camera
+    cameras:
+      - camera.office
   - condition: config
     paths:
-      - "menu.style"
+      - 'menu.style'
   - condition: display_mode
     display_mode: single
   - condition: expand
@@ -416,7 +429,6 @@ conditions:
   - condition: media_loaded
     media_loaded: true
   - condition: microphone
-    connected: true
     muted: true
   - condition: numeric_state
     entity: sensor.office_temperature
@@ -435,8 +447,8 @@ conditions:
     users:
       - 581fca7fdc014b8b894519cc531f9a04
   - condition: user_agent
-    user_agent: "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36"
-    user_agent_re: "Chrome/"
+    user_agent: 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36'
+    user_agent_re: 'Chrome/'
     casting: true
     companion: true
   - condition: view