v0.7.5: arrow keys, image request fix, deepseek-flash vision, musl CI

TUI keys: register both CSI and SS3 forms of the cursor/Home/End keys and
the xterm modifier sequences when terminfo lacks them, so an arrow sent in
the "other" form no longer turns into Esc + a typed letter. Up/Down move by
visual (soft-wrapped) row, and the draft survives a trip through history.
scripts/tui_keys drives the TUI in a pty to check all of this.

Images: text inside a multimodal content array is now a {"type":"text"}
part; DeepSeek rejected the bare string with HTTP 422. deepseek-flash
(and its deepseek-chat / deepseek-reasoner aliases) read images, so the
registry marks them vision; deepseek-v4-pro stays text only.

CI: models.c lost _DEFAULT_SOURCE in 0.7.0 and gmtime_r broke the musl
build; tests sleep with poll() instead of usleep for the same reason.

src/tui.c

@@ -378,6 +378,7 @@ typedef struct {
   char *prompt_hist[PROMPT_HIST_CAP];
   int prompt_hist_n;
   int hist_browse;
+  char *hist_draft; /* the live input while browsing */
 
   /* Busy-turn FIFO */
   char *queue[QUEUE_CAP];
@@ -3163,28 +3164,16 @@ static size_t word_right(const tui_t *t, size_t at) {
   return at;
 }
 
-/* Move to the previous/next logical line keeping the column (in chars).
- * Returns 0 when already on the first/last line. */
+static size_t input_hit(const tui_t *t, int want_row, int want_col);
+
+/* Move to the previous/next visual row (soft-wrapped or not) keeping the
+ * screen column. Returns 0 when already on the first/last row. */
 static int input_line_move(tui_t *t, int dir) {
-  size_t ls = line_start(t, t->cur);
-  int col = 0;
-  for (size_t i = ls; i < t->cur; i += next_len(t, i))
-    col++;
-  size_t target;
-  if (dir < 0) {
-    if (ls == 0)
-      return 0;
-    target = line_start(t, ls - 1);
-  } else {
-    size_t le = line_end(t, t->cur);
-    if (le >= t->in_len)
-      return 0;
-    target = le + 1;
-  }
-  size_t te = line_end(t, target);
-  while (col-- > 0 && target < te)
-    target += next_len(t, target);
-  t->cur = target;
+  int cr, cc;
+  int rows = input_layout(t, NULL, NULL, &cr, &cc);
+  if (cr + dir < 0 || cr + dir >= rows)
+    return 0;
+  t->cur = input_hit(t, cr + dir, cc);
   return 1;
 }
 
@@ -5854,7 +5843,7 @@ static int submit_input(tui_t *t, int busy) {
 static size_t input_hit(const tui_t *t, int want_row, int want_col) {
   int row = 0, col = IN_COL;
   int right = (t->in_w > 0 ? t->in_w : t->cols) - 2;
-  size_t i = 0, best = t->in_len;
+  size_t i = 0, best = t->in_len, last = 0;
   while (i < t->in_len) {
     if (row == want_row && col >= want_col)
       return i;
@@ -5873,12 +5862,14 @@ static size_t input_hit(const tui_t *t, int want_row, int want_col) {
     utf8_decode(t->inbuf + i, t->in_len - i, &wc, &eaten);
     int cw = utf8_width(wc == L'\t' ? L' ' : wc);
     if (col + cw > right && col > IN_COL) {
+      /* offset i would be drawn at the start of the next row */
       if (row == want_row)
-        return i;
+        return last;
       row++;
       col = IN_COL;
     }
     best = i + eaten;
+    last = i;
     col += cw;
     i += eaten;
   }
@@ -6395,29 +6386,65 @@ static int g_k_alt_up, g_k_alt_down, g_k_ctrl_home, g_k_ctrl_end,
     g_k_ctrl_up, g_k_ctrl_down, g_k_ctrl_left, g_k_ctrl_right, g_k_alt_left,
     g_k_alt_right, g_k_ctrl_dc, g_k_alt_dc;
 
-static int ext_key(const char *cap) {
+/* The terminfo key, else the xterm sequence bound to our own code `own`. */
+static int ext_key(const char *cap, const char *xterm, int own) {
   char *s = tigetstr(cap);
-  if (!s || s == (char *)-1)
-    return 0;
-  int k = key_defined(s);
-  return k > 0 ? k : 0;
+  int k = s && s != (char *)-1 ? key_defined(s) : 0;
+  if (k > 0)
+    return k;
+#ifndef _WIN32
+  k = key_defined(xterm);
+  if (k > 0)
+    return k;
+  if (k == 0 && define_key(xterm, own) == OK)
+    return own;
+#else
+  (void)xterm, (void)own;
+#endif
+  return 0;
+}
+#endif
+
+#if defined(NCURSES_VERSION) && !defined(_WIN32)
+/* Terminfo lists one form per key, but terminals disagree: cursor keys come
+ * as CSI or SS3 whatever DECCKM says (tmux, mosh, a wrong TERM), Home/End as
+ * CSI H, SS3 H or CSI 1~/7~. Unknown forms would be read as Esc + text. */
+static void vt_keys_init(void) {
+  static const struct {
+    const char *seq;
+    int key;
+  } K[] = {
+      {"\033[A", KEY_UP},     {"\033OA", KEY_UP},     {"\033[B", KEY_DOWN},
+      {"\033OB", KEY_DOWN},   {"\033[C", KEY_RIGHT},  {"\033OC", KEY_RIGHT},
+      {"\033[D", KEY_LEFT},   {"\033OD", KEY_LEFT},   {"\033[H", KEY_HOME},
+      {"\033OH", KEY_HOME},   {"\033[1~", KEY_HOME},  {"\033[7~", KEY_HOME},
+      {"\033[F", KEY_END},    {"\033OF", KEY_END},    {"\033[4~", KEY_END},
+      {"\033[8~", KEY_END},   {"\033[2~", KEY_IC},    {"\033[3~", KEY_DC},
+      {"\033[5~", KEY_PPAGE}, {"\033[6~", KEY_NPAGE}, {"\033[Z", KEY_BTAB},
+      {"\033[1;2A", KEY_SR},  {"\033[1;2B", KEY_SF},  {"\033[1;2C", KEY_SRIGHT},
+      {"\033[1;2D", KEY_SLEFT},
+  };
+  for (size_t i = 0; i < sizeof(K) / sizeof(K[0]); i++)
+    if (key_defined(K[i].seq) == 0)
+      define_key(K[i].seq, K[i].key);
 }
 #endif
 
 static void keys_init(void) {
 #ifdef NCURSES_VERSION
-  g_k_alt_up = ext_key("kUP3");
-  g_k_alt_down = ext_key("kDN3");
-  g_k_ctrl_home = ext_key("kHOM5");
-  g_k_ctrl_end = ext_key("kEND5");
-  g_k_ctrl_up = ext_key("kUP5");
-  g_k_ctrl_down = ext_key("kDN5");
-  g_k_ctrl_left = ext_key("kLFT5");
-  g_k_ctrl_right = ext_key("kRIT5");
-  g_k_alt_left = ext_key("kLFT3");
-  g_k_alt_right = ext_key("kRIT3");
-  g_k_ctrl_dc = ext_key("kDC5");
-  g_k_alt_dc = ext_key("kDC3");
+  int own = KEY_OWN_BASE + 4; /* up to KEY_KITTY_BASE - 1 */
+  g_k_alt_up = ext_key("kUP3", "\033[1;3A", own++);
+  g_k_alt_down = ext_key("kDN3", "\033[1;3B", own++);
+  g_k_ctrl_home = ext_key("kHOM5", "\033[1;5H", own++);
+  g_k_ctrl_end = ext_key("kEND5", "\033[1;5F", own++);
+  g_k_ctrl_up = ext_key("kUP5", "\033[1;5A", own++);
+  g_k_ctrl_down = ext_key("kDN5", "\033[1;5B", own++);
+  g_k_ctrl_left = ext_key("kLFT5", "\033[1;5D", own++);
+  g_k_ctrl_right = ext_key("kRIT5", "\033[1;5C", own++);
+  g_k_alt_left = ext_key("kLFT3", "\033[1;3D", own++);
+  g_k_alt_right = ext_key("kRIT3", "\033[1;3C", own++);
+  g_k_ctrl_dc = ext_key("kDC5", "\033[3;5~", own++);
+  g_k_alt_dc = ext_key("kDC3", "\033[3;3~", own++);
 #endif
 }
 
@@ -6630,6 +6657,7 @@ static void tui_free(tui_t *t) {
   queue_free_all(t);
   for (int i = 0; i < t->prompt_hist_n; i++)
     free(t->prompt_hist[i]);
+  free(t->hist_draft);
   for (int i = 0; i < t->nfiles; i++)
     free(t->files[i]);
   free(t->files);
@@ -6720,6 +6748,7 @@ int cst_tui_run(cst_agent_t *agent) {
   /* the Windows console driver reads key events, not VT sequences */
   define_key("\033[200~", KEY_PASTE_BEGIN);
   define_key("\033[201~", KEY_PASTE_END);
+  vt_keys_init();
   printf("\033[?2004h");
   fflush(stdout);
   kitty_init();
@@ -7032,15 +7061,22 @@ int cst_tui_run(cst_agent_t *agent) {
           if (t.prompt_hist_n <= 0)
             continue;
           int idx = t.hist_browse;
+          if (idx < 0) {
+            free(t.hist_draft);
+            t.hist_draft = strdup(t.inbuf);
+          }
           idx = idx < 0 ? t.prompt_hist_n - 1 : (idx > 0 ? idx - 1 : 0);
           hist_load_into_input(&t, idx);
         } else {
           if (t.hist_browse < 0)
             continue;
-          if (t.hist_browse + 1 >= t.prompt_hist_n)
-            input_clear(&t);
-          else
+          if (t.hist_browse + 1 >= t.prompt_hist_n) {
+            input_set(&t, t.hist_draft);
+            free(t.hist_draft);
+            t.hist_draft = NULL;
+          } else {
             hist_load_into_input(&t, t.hist_browse + 1);
+          }
         }
         after_edit(&t);
         continue;