feat(lsp): initial support for textDocument/rename

flow keybinds: changes f2 from toggle_input_mode to rename_symbol and
moves toggle_input_mode command to ctrl+shift+f2 (since ctrl+f2 is
already bound to insert_command_name)

the replacement text is hard coded for now. i've checked that replace
works with zls and pylsp which send WorkspaceEdit response messages in
different shapes - zls sends shape `{"changes": {}}` while pylsp sends
`{"documentChanges": []}`.

currently the 'rename_symbol_item' commands are sent one at a time.
however they should be buffered and be performed between one
buf_for_update, update_buf pair.  this will be addressed in a follow up.

src/tui/editor.zig

@@ -4222,6 +4222,13 @@ pub const Editor = struct {
     }
     pub const completion_meta = .{ .description = "Language: Show completions at cursor" };
 
+    pub fn rename_symbol(self: *Self, _: Context) Result {
+        const file_path = self.file_path orelse return;
+        const primary = self.get_primary();
+        return project_manager.rename_symbol(file_path, primary.cursor.row, primary.cursor.col);
+    }
+    pub const rename_symbol_meta = .{ .description = "Language: Rename symbol at cursor" };
+
     pub fn hover(self: *Self, _: Context) Result {
         const primary = self.get_primary();
         return self.hover_at(primary.cursor.row, primary.cursor.col);
@@ -4316,6 +4323,15 @@ pub const Editor = struct {
         self.need_render();
     }
 
+    pub fn rename_symbol_item(self: *Self, sel: Selection, new_text: []const u8) Result {
+        self.get_primary().selection = sel;
+        const buf = try self.buf_for_update();
+        const r1 = try self.delete_selection(buf.root, self.get_primary(), self.allocator);
+        const r2 = try self.insert(r1, self.get_primary(), new_text, self.allocator);
+        try self.update_buf(r2);
+        self.need_render();
+    }
+
     pub fn select(self: *Self, ctx: Context) Result {
         var sel: Selection = .{};
         if (!try ctx.args.match(.{ tp.extract(&sel.begin.row), tp.extract(&sel.begin.col), tp.extract(&sel.end.row), tp.extract(&sel.end.col) }))

src/tui/mainview.zig

@@ -554,6 +554,32 @@ const cmds = struct {
     }
     pub const add_diagnostic_meta = .{ .arguments = &.{ .string, .string, .string, .string, .integer, .integer, .integer, .integer, .integer } };
 
+    pub fn rename_symbol_item(self: *Self, ctx: Ctx) Result {
+        var file_uri: []const u8 = undefined;
+        var sel: ed.Selection = .{};
+        var new_text: []const u8 = undefined;
+        if (!try ctx.args.match(.{
+            tp.extract(&file_uri),
+            tp.extract(&sel.begin.row),
+            tp.extract(&sel.begin.col),
+            tp.extract(&sel.end.row),
+            tp.extract(&sel.end.col),
+            tp.extract(&new_text),
+        })) return error.InvalidRenameSymbolArgument;
+        file_uri = project_manager.normalize_file_path(file_uri);
+        if (self.get_active_editor()) |editor| {
+            // TODO match correctly. endsWith() isn't correct because path is a
+            // short, relative path while file_uri is an absolute path starting with 'file://'
+            const match = if (editor.file_path) |path| std.mem.endsWith(u8, file_uri, path) else false;
+            if (match) {
+                try editor.rename_symbol_item(sel, new_text);
+            } else {
+                // TODO perform renames in other files
+            }
+        }
+    }
+    pub const rename_symbol_item_meta = .{ .arguments = &.{ .string, .integer, .integer, .integer, .integer, .string } };
+
     pub fn clear_diagnostics(self: *Self, ctx: Ctx) Result {
         var file_path: []const u8 = undefined;
         if (!try ctx.args.match(.{tp.extract(&file_path)})) return error.InvalidClearDiagnosticsArgument;