fix: apply missed media/runtime follow-ups from merged PRs

docs/nodes/media-understanding.md

@@ -123,6 +123,7 @@ Recommended defaults:
 Rules:
 
 - If media exceeds `maxBytes`, that model is skipped and the **next model is tried**.
+- Audio files smaller than **1024 bytes** are treated as empty/corrupt and skipped before provider/CLI transcription.
 - If the model returns more than `maxChars`, output is trimmed.
 - `prompt` defaults to simple “Describe the {media}.” plus the `maxChars` guidance (image/video only).
 - If `<capability>.enabled: true` but no models are configured, OpenClaw tries the
@@ -160,6 +161,20 @@ To disable auto-detection, set:
 
 Note: Binary detection is best-effort across macOS/Linux/Windows; ensure the CLI is on `PATH` (we expand `~`), or set an explicit CLI model with a full command path.
 
+### Proxy environment support (provider models)
+
+When provider-based **audio** and **video** media understanding is enabled, OpenClaw
+honors standard outbound proxy environment variables for provider HTTP calls:
+
+- `HTTPS_PROXY`
+- `HTTP_PROXY`
+- `https_proxy`
+- `http_proxy`
+
+If no proxy env vars are set, media understanding uses direct egress.
+If the proxy value is malformed, OpenClaw logs a warning and falls back to direct
+fetch.
+
 ## Capabilities (optional)
 
 If you set `capabilities`, the entry only runs for those media types. For shared

docs/tools/plugin.md

@@ -90,6 +90,22 @@ Notes:
 - Returns PCM audio buffer + sample rate. Plugins must resample/encode for providers.
 - Edge TTS is not supported for telephony.
 
+For STT/transcription, plugins can call:
+
+```ts
+const { text } = await api.runtime.stt.transcribeAudioFile({
+  filePath: "/tmp/inbound-audio.ogg",
+  cfg: api.config,
+  // Optional when MIME cannot be inferred reliably:
+  mime: "audio/ogg",
+});
+```
+
+Notes:
+
+- Uses core media-understanding audio configuration (`tools.media.audio`) and provider fallback order.
+- Returns `{ text: undefined }` when no transcription output is produced (for example skipped/unsupported input).
+
 ## Discovery & precedence
 
 OpenClaw scans, in order: