config: a workstation block, dropped when it names no address (V-485)

Health defaults to the supervisor's /health rather than llama-server's,
because mavgpud is what answers 503 while the card is held.

internal/config/config.go

@@ -224,6 +224,11 @@ type Config struct {
 	// See SearchConfig.
 	Search *SearchConfig `json:"search,omitempty"`
 
+	// Workstation — the big model on the owner's desktop, preferred over the
+	// resident one when its GPU is free. nil / absent / url empty ⇒ homesrv
+	// behaves exactly as it does today. See WorkstationConfig.
+	Workstation *WorkstationConfig `json:"workstation,omitempty"`
+
 	// Praxis — the ecosystem attention-state service. When configured, maven
 	// calls the Praxis HTTP tools API for attention listing and item lifecycle.
 	// Maven never touches Praxis's database directly (ecosystem invariant: no
@@ -1105,6 +1110,44 @@ const (
 	DefaultKiwixSnippetRunes = 1500
 )
 
+// WorkstationConfig — the big model on the owner's desktop (bugmachine, a
+// 7900 GRE with 16GB), fronted by mavgpud.
+//
+// homesrv cannot grow a GPU, so the resident Qwen3-1.7B is the floor and this
+// is the preferred model above it (owner's call, 2026-08-02, docs/offload.md).
+// The workstation is never assumed up: its card is often held by a CPT run and
+// the machine sleeps. No block, or an empty URL, and homesrv behaves exactly as
+// it does today.
+//
+// Only the prompt crosses the LAN, and the workstation is not "the box". The
+// rules in CLAUDE.md about what may leave still apply.
+type WorkstationConfig struct {
+	// URL — where mavgpud listens, e.g. "http://192.168.1.105:8080". Empty ⇒
+	// the whole block is normalised to nil and nothing probes anything.
+	URL string `json:"url,omitempty"`
+
+	// Health — the admission endpoint. Empty ⇒ URL + "/health", which is what
+	// mavgpud serves. It answers 503 while the card is held, and that is the
+	// signal, so it must be the supervisor's endpoint and not llama-server's.
+	Health string `json:"health,omitempty"`
+
+	// Probe — how often admission is re-checked. 0 ⇒ DefaultWorkstationProbe.
+	// Nothing on the hot path waits for it: the answer is cached and read
+	// atomically, so this only sets how late Maven notices the card came back.
+	Probe Duration `json:"probe,omitempty"`
+
+	// Timeout — the per-request budget for a completion on the workstation.
+	// 0 ⇒ DefaultWorkstationTimeout. A big model on a LAN host is slower than
+	// the resident one, and a request that overruns falls back to the floor.
+	Timeout Duration `json:"timeout,omitempty"`
+}
+
+// Workstation defaults, applied in Normalise.
+const (
+	DefaultWorkstationProbe   = 15 * time.Second
+	DefaultWorkstationTimeout = 90 * time.Second
+)
+
 // SearchConfig — the self-hosted SearXNG instance she searches with.
 //
 // External search is allowed and off unless configured (CLAUDE.md). Configuring
@@ -1500,6 +1543,24 @@ func (c *Config) applyDefaults() {
 		}
 	}
 
+	// No address, no preferred model. An unconfigured workstation is the
+	// default deploy and must be indistinguishable from today.
+	if c.Workstation != nil && strings.TrimSpace(c.Workstation.URL) == "" {
+		c.Workstation = nil
+	}
+	if c.Workstation != nil {
+		w := c.Workstation
+		if strings.TrimSpace(w.Health) == "" {
+			w.Health = strings.TrimRight(w.URL, "/") + "/health"
+		}
+		if w.Probe <= 0 {
+			w.Probe = Duration(DefaultWorkstationProbe)
+		}
+		if w.Timeout <= 0 {
+			w.Timeout = Duration(DefaultWorkstationTimeout)
+		}
+	}
+
 	if c.Voice != nil {
 		if c.Voice.RouterThreshold <= 0 {
 			c.Voice.RouterThreshold = DefaultRouterThreshold

internal/config/config_test.go

@@ -413,3 +413,56 @@ func TestNormaliseFillsKiwixDefaults(t *testing.T) {
 		t.Error("rewrite: false was not honoured")
 	}
 }
+
+// A workstation with no address is not a workstation. The unconfigured deploy
+// must be indistinguishable from today, so the block is dropped rather than
+// left to fail one probe at a time.
+func TestNormaliseDropsAddresslessWorkstation(t *testing.T) {
+	for _, tc := range []struct {
+		name string
+		in   *WorkstationConfig
+	}{
+		{"no url", &WorkstationConfig{Probe: Duration(time.Second)}},
+		{"blank url", &WorkstationConfig{URL: "   "}},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			c := &Config{Workstation: tc.in}
+			c.applyDefaults()
+			if c.Workstation != nil {
+				t.Errorf("kept an unusable workstation block: %+v", c.Workstation)
+			}
+		})
+	}
+}
+
+// The health endpoint defaults to the supervisor's, not llama-server's: mavgpud
+// answers 503 while the card is held, and that refusal is the whole signal.
+func TestNormaliseFillsWorkstationDefaults(t *testing.T) {
+	c := &Config{Workstation: &WorkstationConfig{URL: "http://192.168.1.105:8080/"}}
+	c.applyDefaults()
+	if c.Workstation == nil {
+		t.Fatal("dropped a usable workstation block")
+	}
+	if got, want := c.Workstation.Health, "http://192.168.1.105:8080/health"; got != want {
+		t.Errorf("Health = %q, want %q", got, want)
+	}
+	if time.Duration(c.Workstation.Probe) != DefaultWorkstationProbe {
+		t.Errorf("Probe = %s, want %s", time.Duration(c.Workstation.Probe), DefaultWorkstationProbe)
+	}
+	if time.Duration(c.Workstation.Timeout) != DefaultWorkstationTimeout {
+		t.Errorf("Timeout = %s, want %s", time.Duration(c.Workstation.Timeout), DefaultWorkstationTimeout)
+	}
+}
+
+// An explicit health URL is left alone: the supervisor may sit behind something
+// that does not put /health at the root.
+func TestNormaliseKeepsExplicitWorkstationHealth(t *testing.T) {
+	c := &Config{Workstation: &WorkstationConfig{
+		URL:    "http://192.168.1.105:8080",
+		Health: "http://192.168.1.105:9000/ready",
+	}}
+	c.applyDefaults()
+	if got, want := c.Workstation.Health, "http://192.168.1.105:9000/ready"; got != want {
+		t.Errorf("Health = %q, want %q", got, want)
+	}
+}