one gesture beside the reply corrects a turn (V-630)

Two buttons' worth of cost: wrong, or wrong and it should have been this.
The second is worth much more and is not required to give the first, so a
turn marked wrong with no target still lands as a usable negative.

The target is one of the seven intents, never free text: an unroutable label
would enter the one table V-632 fits prototypes from.

/api/correct is not behind the step-up gate. It reaches no router, no model
and no act path, and a correction that costs a passkey tap is one that does
not get made.

cmd/mavweb/chat.go

@@ -2,12 +2,15 @@ package main
 
 import (
 	_ "embed"
+	"errors"
 	"log"
 	"net/http"
 	"net/url"
+	"strconv"
 	"strings"
 
 	"github.com/kami/maven/internal/ipc"
+	"github.com/kami/maven/internal/router"
 	"github.com/kami/maven/internal/webauthn"
 )
 
@@ -25,6 +28,21 @@ type chatMsg struct {
 	// Source — the query source that claimed the turn, shown as a badge beside
 	// the reply. Empty for a turn no source claimed (V-539).
 	Source string
+	// TraceID anchors the correction gesture (V-630). Non-zero ⇒ the turn was
+	// persisted and can be corrected in one click. 0 ⇒ no correction is offered,
+	// which is honest: a box with no database has no turn to correct.
+	TraceID int64
+	// Corrected — the owner already corrected this turn, so the page says thank
+	// you instead of offering the buttons again.
+	Corrected string
+}
+
+// correctionTargets — the seven public intents, in the order the buttons are
+// shown. Read from internal/router rather than typed out, so a new intent cannot
+// exist without a way to correct a turn into it.
+var correctionTargets = []router.Intent{
+	router.IntentFact, router.IntentNote, router.IntentReminder,
+	router.IntentQuery, router.IntentAct, router.IntentChat, router.IntentSystem,
 }
 
 // handleChatPage renders the chat conversation page.
@@ -38,12 +56,21 @@ func handleChatPage(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI) {
 		msgs = append(msgs, chatMsg{Role: "user", Text: q})
 	}
 	if reply := r.URL.Query().Get("r"); reply != "" {
-		msgs = append(msgs, chatMsg{Role: "assistant", Text: reply, Source: r.URL.Query().Get("s")})
+		id, _ := strconv.ParseInt(r.URL.Query().Get("t"), 10, 64)
+		msgs = append(msgs, chatMsg{
+			Role: "assistant", Text: reply, Source: r.URL.Query().Get("s"),
+			TraceID: id, Corrected: r.URL.Query().Get("c"),
+		})
 	}
+	// UserText rides beside the messages so the correction form can hand the
+	// conversation back on the redirect: this page has no session and no JS, so
+	// what is on screen is what the query params carry.
 	renderPage(w, chatTmpl, struct {
 		Error    string
 		Messages []chatMsg
-	}{Messages: msgs})
+		Targets  []router.Intent
+		UserText string
+	}{Messages: msgs, Targets: correctionTargets, UserText: r.URL.Query().Get("q")})
 }
 
 // handleChatAPI processes a chat message POST and redirects back to /chat.
@@ -88,5 +115,77 @@ func handleChatAPI(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI, ses
 	if reply.Source != "" {
 		dest += "&s=" + url.QueryEscape(reply.Source)
 	}
+	// The trace id rides along so the reply can carry a correction gesture
+	// (V-630). Absent when nothing persisted, and the page then offers none.
+	if reply.TraceID != 0 {
+		dest += "&t=" + strconv.FormatInt(reply.TraceID, 10)
+	}
 	http.Redirect(w, r, dest, http.StatusSeeOther)
 }
+
+// handleCorrectAPI records that the last turn was routed wrongly (V-630).
+//
+// A correction is the only supervised signal this box gets, and everything else
+// in the trace accumulates on its own. So the gesture has to cost nothing: one
+// POST from the reply he is already looking at, carrying the trace id and
+// optionally the intent it should have been. An unstated target is accepted,
+// because a turn marked wrong with no target is still a usable negative.
+//
+// Not step-up gated, unlike POST /api/chat. Writing a label reaches no router,
+// no model and no act path; it writes one row nothing executes from. Gating it
+// would price the gesture out of being used, which is the one thing that makes
+// it worthless.
+func handleCorrectAPI(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "POST only", http.StatusMethodNotAllowed)
+		return
+	}
+	if !requireCore(w, core, "correct") {
+		return
+	}
+	id, err := strconv.ParseInt(strings.TrimSpace(r.FormValue("trace_id")), 10, 64)
+	if err != nil || id <= 0 {
+		http.Error(w, "trace_id required", http.StatusBadRequest)
+		return
+	}
+	shouldBe := strings.TrimSpace(r.FormValue("should_be"))
+	// Only one of the seven, or nothing. Free text here would put an unroutable
+	// label in the one table V-632 fits prototypes from.
+	if shouldBe != "" && !isCorrectionTarget(shouldBe) {
+		http.Error(w, "should_be must be one of the seven intents", http.StatusBadRequest)
+		return
+	}
+	if err := core.CorrectTurn(r.Context(), id, shouldBe); err != nil {
+		log.Printf("correct turn %d: %v", id, err)
+		// A turn past the retention bound is gone, and saying so is different
+		// from saying the write broke.
+		if errors.Is(err, ipc.ErrNoSuchTrace) {
+			http.Error(w, "that turn is no longer stored", http.StatusNotFound)
+			return
+		}
+		http.Error(w, "correction failed", http.StatusBadGateway)
+		return
+	}
+	stamp := shouldBe
+	if stamp == "" {
+		stamp = "wrong"
+	}
+	// Back to the conversation he was in, with the turn still on screen. The
+	// query params carry it, so the correction is preserved by re-sending them.
+	dest := "/chat?q=" + url.QueryEscape(r.FormValue("q")) +
+		"&r=" + url.QueryEscape(r.FormValue("rep")) + "&c=" + url.QueryEscape(stamp)
+	if s := r.FormValue("s"); s != "" {
+		dest += "&s=" + url.QueryEscape(s)
+	}
+	http.Redirect(w, r, dest, http.StatusSeeOther)
+}
+
+// isCorrectionTarget — one of the seven, and nothing else.
+func isCorrectionTarget(s string) bool {
+	for _, t := range correctionTargets {
+		if string(t) == s {
+			return true
+		}
+	}
+	return false
+}

cmd/mavweb/chat.html

@@ -5,6 +5,21 @@
 <div class="scroll chat-scroll" id=chatHistory>
 {{range .Messages}}
   <div class="chat-msg {{.Role}}"><strong>{{if eq .Role "user"}}you{{else}}maven{{end}}:</strong> {{.Text}}{{if .Source}} <span class="badge badge-accent" title="the query source that claimed this turn">{{.Source}}</span>{{end}}</div>
+  {{if and (eq .Role "assistant") .TraceID}}
+  {{if .Corrected}}
+  <div class=chat-correct><span class="badge badge-ok" title="the label is kept; the transcript still expires in 14 days">corrected: {{.Corrected}}</span></div>
+  {{else}}
+  <form method=post action=/api/correct class=chat-correct>
+    <input type=hidden name=trace_id value="{{.TraceID}}">
+    <input type=hidden name=q value="{{$.UserText}}">
+    <input type=hidden name=rep value="{{.Text}}">
+    <input type=hidden name=s value="{{.Source}}">
+    <button class="btn btn-sm" title="wrong, and I am not saying what it was">wrong</button>
+    <span class=chat-correct-label>should have been:</span>
+    {{range $.Targets}}<button class="btn btn-sm btn-muted" name=should_be value="{{.}}">{{.}}</button>{{end}}
+  </form>
+  {{end}}
+  {{end}}
 {{else}}
   <div class=empty>
     <svg class=icon width="20" height="20"><use href="/ethos-icons.svg#i-message"/></svg>

cmd/mavweb/correct_test.go

@@ -0,0 +1,146 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"testing"
+
+	"github.com/kami/maven/internal/ipc"
+)
+
+// correctCore records the correction the handler sends.
+type correctCore struct {
+	ipc.UnimplementedCoreAPI
+	traceID  int64
+	shouldBe string
+	called   bool
+	err      error
+}
+
+func (c *correctCore) CorrectTurn(_ context.Context, traceID int64, shouldBe string) error {
+	c.called, c.traceID, c.shouldBe = true, traceID, shouldBe
+	return c.err
+}
+
+func postCorrect(form url.Values) *http.Request {
+	req := httptest.NewRequest(http.MethodPost, "/api/correct", strings.NewReader(form.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	return req
+}
+
+// The full gesture: wrong, and it should have been a fact.
+func TestCorrectAPIWithTarget(t *testing.T) {
+	core := &correctCore{}
+	rr := httptest.NewRecorder()
+	handleCorrectAPI(rr, postCorrect(url.Values{
+		"trace_id": {"42"}, "should_be": {"fact"}, "q": {"поужинал"}, "rep": {"поняла"},
+	}), core)
+
+	if rr.Code != http.StatusSeeOther {
+		t.Fatalf("status %d, want 303; body=%s", rr.Code, rr.Body.String())
+	}
+	if core.traceID != 42 || core.shouldBe != "fact" {
+		t.Errorf("corrected trace %d to %q", core.traceID, core.shouldBe)
+	}
+	// The turn stays on screen, and the page says it was corrected.
+	loc := rr.Header().Get("Location")
+	if !strings.Contains(loc, "c=fact") || !strings.Contains(loc, "q=") {
+		t.Errorf("redirect %q loses the turn or the correction", loc)
+	}
+}
+
+// The cheap half. A turn marked wrong with no target is still a usable negative,
+// and it must not cost more to give than the full answer.
+func TestCorrectAPIWithNoTarget(t *testing.T) {
+	core := &correctCore{}
+	rr := httptest.NewRecorder()
+	handleCorrectAPI(rr, postCorrect(url.Values{"trace_id": {"7"}}), core)
+
+	if rr.Code != http.StatusSeeOther {
+		t.Fatalf("status %d, want 303", rr.Code)
+	}
+	if !core.called || core.shouldBe != "" {
+		t.Errorf("called=%v shouldBe=%q, want an untargeted negative recorded", core.called, core.shouldBe)
+	}
+	if !strings.Contains(rr.Header().Get("Location"), "c=wrong") {
+		t.Errorf("redirect %q does not say the turn was marked wrong", rr.Header().Get("Location"))
+	}
+}
+
+// Free text here would put an unroutable label in the one table V-632 fits
+// prototypes from.
+func TestCorrectAPIRejectsUnknownTarget(t *testing.T) {
+	core := &correctCore{}
+	rr := httptest.NewRecorder()
+	handleCorrectAPI(rr, postCorrect(url.Values{"trace_id": {"7"}, "should_be": {"погода"}}), core)
+
+	if rr.Code != http.StatusBadRequest {
+		t.Fatalf("status %d, want 400", rr.Code)
+	}
+	if core.called {
+		t.Error("wrote a label for a target that is not one of the seven")
+	}
+}
+
+func TestCorrectAPINeedsTraceID(t *testing.T) {
+	for _, form := range []url.Values{{}, {"trace_id": {"0"}}, {"trace_id": {"nope"}}} {
+		core := &correctCore{}
+		rr := httptest.NewRecorder()
+		handleCorrectAPI(rr, postCorrect(form), core)
+		if rr.Code != http.StatusBadRequest {
+			t.Errorf("form %v: status %d, want 400", form, rr.Code)
+		}
+		if core.called {
+			t.Errorf("form %v: reached the core", form)
+		}
+	}
+}
+
+// A write that broke is not a turn that expired, and the two must not read the
+// same to the owner deciding whether to correct again.
+func TestCorrectAPIReportsFailure(t *testing.T) {
+	core := &correctCore{err: errors.New("disk is full")}
+	rr := httptest.NewRecorder()
+	handleCorrectAPI(rr, postCorrect(url.Values{"trace_id": {"9"}, "should_be": {"note"}}), core)
+	if rr.Code != http.StatusBadGateway {
+		t.Fatalf("status %d, want 502", rr.Code)
+	}
+}
+
+// A trace past the retention bound is gone, and the surface says that.
+func TestCorrectAPIExpiredTurn(t *testing.T) {
+	core := &correctCore{err: ipc.ErrNoSuchTrace}
+	rr := httptest.NewRecorder()
+	handleCorrectAPI(rr, postCorrect(url.Values{"trace_id": {"9"}, "should_be": {"note"}}), core)
+	if rr.Code != http.StatusNotFound {
+		t.Fatalf("status %d, want 404", rr.Code)
+	}
+}
+
+func TestCorrectAPIPostOnly(t *testing.T) {
+	rr := httptest.NewRecorder()
+	handleCorrectAPI(rr, httptest.NewRequest(http.MethodGet, "/api/correct", nil), &correctCore{})
+	if rr.Code != http.StatusMethodNotAllowed {
+		t.Fatalf("status %d, want 405", rr.Code)
+	}
+}
+
+// Every one of the seven intents has a button, so a new intent cannot exist with
+// no way to correct a turn into it.
+func TestCorrectionTargetsAreTheSeven(t *testing.T) {
+	if len(correctionTargets) != 7 {
+		t.Fatalf("%d targets, want the seven public intents", len(correctionTargets))
+	}
+	for _, want := range []string{"fact", "note", "reminder", "query", "act", "chat", "system"} {
+		if !isCorrectionTarget(want) {
+			t.Errorf("%s is not offered", want)
+		}
+	}
+	if isCorrectionTarget("") {
+		t.Error("empty is not a target: it is the absence of one, handled separately")
+	}
+}

cmd/mavweb/main.go

@@ -210,6 +210,13 @@ func main() {
 	mux.HandleFunc("/routines", gatedPage(handleRoutines))
 	mux.HandleFunc("/api/chat", gatedPage(handleChatAPI))
 	mux.HandleFunc("/api/revert", gatedPage(handleRevert))
+	// POST /api/correct is deliberately NOT on the step-up list (V-630). It
+	// reaches no router, no model and no act path: it writes one label row that
+	// nothing executes from. A correction that costs a passkey tap is a
+	// correction the owner does not make, and then the table stays empty.
+	mux.HandleFunc("/api/correct", func(w http.ResponseWriter, r *http.Request) {
+		handleCorrectAPI(w, r, core)
+	})
 	mux.HandleFunc("/models", func(w http.ResponseWriter, r *http.Request) {
 		handleModels(w, r, core, swapConn, stepUpSession, *requireStepUp)
 	})

cmd/mavweb/static/ui.css

@@ -702,6 +702,11 @@ details[open] > summary { margin-bottom: var(--space-1); }
 .chat-form { display: flex; gap: var(--space-2); }
 .chat-form input { flex: 1; }
 .chat-scroll { max-height: 60vh; overflow-y: auto; margin-bottom: var(--space-4); }
+/* The correction gesture (V-630). Wraps on a phone rather than scrolling: it is
+   one row of small buttons, and a gesture that has to be panned to is not one. */
+.chat-correct { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-1);
+  padding: 0 var(--space-3) var(--space-2); margin-top: calc(-1 * var(--space-1)); margin-bottom: var(--space-2); }
+.chat-correct-label { font-size: var(--fs-xs); color: var(--text-machine); margin-left: var(--space-2); }
 
 /* ── Key-value grid ── */
 .kv { display: grid; grid-template-columns: auto 1fr; gap: var(--space-1) var(--space-3); font-size: var(--fs-sm); }