v0.4.12 : fix reasoning Laguna S 2.1 (reponse qui partait dans le thinking)

Les modeles hybrides (Laguna S 2.1) qui repondent SANS reflechir n envoyaient
que `content` (ni reasoning_content, ni </think>, retire par le backend a
--reasoning-format). jean, avec REASONING=on, supposait un bloc <think> ouvert
par le prompt et vidait toute la reponse dans la bulle thinking. On streame
desormais le contenu en direct par defaut et on ne bascule en reasoning qu au
vu d un </think> reel. La coupe de la queue anti-</think> est realignee sur une
frontiere de rune UTF-8 pour ne plus casser les accents (e -> mojibake).

cmd/jean/versioninfo.json

@@ -3,13 +3,13 @@
     "FileVersion": {
       "Major": 0,
       "Minor": 4,
-      "Patch": 7,
+      "Patch": 12,
       "Build": 0
     },
     "ProductVersion": {
       "Major": 0,
       "Minor": 4,
-      "Patch": 7,
+      "Patch": 12,
       "Build": 0
     },
     "FileFlagsMask": "3f",
@@ -25,7 +25,7 @@
     "LegalCopyright": "Copyright (c) 2026 Jean contributors. MIT License.",
     "OriginalFilename": "jean.exe",
     "ProductName": "Jean",
-    "ProductVersion": "0.4.7",
+    "ProductVersion": "0.4.12",
     "Comments": "https://github.com/nathaninline/jean — projet open source (MIT)"
   },
   "VarFileInfo": {

internal/jean/llm_client.go

@@ -10,6 +10,7 @@ import (
 	"net/http"
 	"sort"
 	"strings"
+	"unicode/utf8"
 )
 
 // Message is one entry in the chat history sent to llama.cpp.
@@ -574,12 +575,21 @@ func runChat(ctx context.Context, messages []Message, temperature float64, caps
 						break
 					}
 				} else {
-					// Inside the prompt-opened <think> block: stream to the
-					// reasoning bubble until the closing </think>, then switch
-					// the remainder to normal content.
+					// The prompt opened a <think> block. Stream `content` LIVE as
+					// the answer, holding back only a short tail that could be the
+					// start of a literal "</think>". A reasoning-aware backend
+					// (llama.cpp with --reasoning-format, Nathan's fork) strips the
+					// think tags server-side, so </think> never appears in content
+					// and the whole answer streams straight through — including
+					// when the model answers WITHOUT thinking (no reasoning_content,
+					// no </think>), which is exactly what used to get dumped into
+					// the reasoning bubble. A vanilla build that leaves the thinking
+					// inline still gets carved at the </think> below.
 					thinkTail.WriteString(ch.Delta.Content)
 					s := thinkTail.String()
 					if i := strings.Index(s, thinkClose); i >= 0 {
+						// Vanilla inline think: reasoning before </think>, answer
+						// after. Route the reasoning to its bubble, drop the tag.
 						reason := s[:i]
 						after := strings.TrimLeft(s[i+len(thinkClose):], "\r\n")
 						thinkOpen = false
@@ -593,13 +603,19 @@ func runChat(ctx context.Context, messages []Message, temperature float64, caps
 							break
 						}
 					} else {
-						// Hold back a tail that could be a partial "</think>".
-						keep := len(thinkClose) - 1
-						if len(s) > keep {
-							emit := s[:len(s)-keep]
+						// No </think> yet: stream as content, holding back a tail
+						// that could be a partial "</think>". Back the cut up to a
+						// UTF-8 rune boundary so a multi-byte char (é, …) is never
+						// split — otherwise the two halves decode as � (mojibake).
+						cut := len(s) - (len(thinkClose) - 1)
+						for cut > 0 && !utf8.RuneStart(s[cut]) {
+							cut--
+						}
+						if cut > 0 {
+							emit := s[:cut]
 							thinkTail.Reset()
-							thinkTail.WriteString(s[len(s)-keep:])
-							if !cb(StreamEvent{Reasoning: emit}) {
+							thinkTail.WriteString(s[cut:])
+							if !cb(StreamEvent{Content: emit}) {
 								aborted = true
 								break
 							}
@@ -608,9 +624,9 @@ func runChat(ctx context.Context, messages []Message, temperature float64, caps
 				}
 			}
 		}
-		// Flush any buffered reasoning if the stream ended mid-think.
+		// Flush the held-back tail (never part of a </think>): it's answer text.
 		if !aborted && thinkOpen && thinkTail.Len() > 0 {
-			cb(StreamEvent{Reasoning: thinkTail.String()})
+			cb(StreamEvent{Content: strings.TrimLeft(thinkTail.String(), "\r\n")})
 		}
 		resp.Body.Close()
 		if aborted {

internal/jean/run.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 )
 
-const Version = "0.4.11"
+const Version = "0.4.12"
 
 // Main est le vrai main() du binaire (cmd/jean ne fait que l'appeler).
 func Main() {