feat(voice-call): route inbound calls per number

docs/plugins/voice-call.md

@@ -110,6 +110,17 @@ Voice-call credentials accept SecretRefs. `plugins.entries.voice-call.config.twi
           fromNumber: "+15550001234", // or TWILIO_FROM_NUMBER for Twilio
           toNumber: "+15550005678",
           sessionScope: "per-phone", // per-phone | per-call
+          numbers: {
+            "+15550009999": {
+              inboundGreeting: "Silver Fox Cards, how can I help?",
+              responseSystemPrompt: "You are a concise baseball card specialist.",
+              tts: {
+                providers: {
+                  openai: { voice: "alloy" },
+                },
+              },
+            },
+          },
 
           twilio: {
             accountSid: "ACxxxxxxxx",
@@ -500,6 +511,57 @@ identity.
 Auto-responses use the agent system. Tune with `responseModel`,
 `responseSystemPrompt`, and `responseTimeoutMs`.
 
+### Per-number Routing
+
+Use `numbers` when one Voice Call plugin receives calls for multiple phone
+numbers and each number should behave like a different line. For example, one
+number can use a casual personal assistant while another uses a business
+persona, a different response agent, and a different TTS voice.
+
+Routes are selected from the provider-supplied dialed `To` number. Keys must be
+E.164 numbers. When a call arrives, Voice Call resolves the matching route once,
+stores the matched route on the call record, and reuses that effective config
+for the greeting, classic auto-response path, realtime consult path, and TTS
+playback. If no route matches, the global Voice Call config is used.
+Outbound calls do not use `numbers`; pass the outbound target, message, and
+session explicitly when initiating the call.
+
+Route overrides currently support:
+
+- `inboundGreeting`
+- `tts`
+- `agentId`
+- `responseModel`
+- `responseSystemPrompt`
+- `responseTimeoutMs`
+
+The `tts` route value deep-merges over the global Voice Call `tts` config, so
+you can usually override only the provider voice:
+
+```json5
+{
+  inboundGreeting: "Hello from the main line.",
+  responseSystemPrompt: "You are the default voice assistant.",
+  tts: {
+    provider: "openai",
+    providers: {
+      openai: { voice: "coral" },
+    },
+  },
+  numbers: {
+    "+15550001111": {
+      inboundGreeting: "Silver Fox Cards, how can I help?",
+      responseSystemPrompt: "You are a concise baseball card specialist.",
+      tts: {
+        providers: {
+          openai: { voice: "alloy" },
+        },
+      },
+    },
+  },
+}
+```
+
 ### Spoken output contract
 
 For auto-responses, Voice Call appends a strict spoken-output contract to