Quote an overridden ldscript name on the link line; note the deliberate board-derived --flash_size

The -T script name was the one user-controlled token on the link line
that skipped shell_token, so a space or dollar sign in a
board_build.ldscript override corrupted the emitted linkflags. The
elf2bin comment now records that --flash_size deliberately stays
board-derived, matching PlatformIO (which reads upload.maximum_size,
not the ldscript).

esphome/build_gen/arduino8266.py

@@ -791,7 +791,8 @@ def write_project(paths: InstalledPaths, ccache: str | None) -> bool:
     link_flags += project_link_flags
     link_flags += [_shell_token(flag) for lib in libraries for flag in lib.link_flags]
     flash_ld = _active_flash_ld_name(flash_ld_name)
-    link_flags += ["-T", flash_ld]
+    # A user-overridden script name re-quotes like every other user token
+    link_flags += ["-T", _shell_token(flash_ld)]
 
     lib_dirs = [Path("ld"), sdk / "lib", sdk / "ld", sdk / "lib" / config.nonosdk]
     lib_dirs += project_lib_dirs
@@ -850,7 +851,9 @@ def write_project(paths: InstalledPaths, ccache: str | None) -> bool:
         "  description = LINK $out",
         "rule elf2bin",
         # --flash_freq 40: every supported board's f_flash is 40 MHz;
-        # re-check on a platform bump
+        # re-check on a platform bump. --flash_size deliberately stays
+        # board-derived, as under PlatformIO (which reads
+        # upload.maximum_size, not the ldscript).
         f"  command = $python {_q(framework / 'tools' / 'elf2bin.py')} --eboot {_q(framework / 'bootloaders' / 'eboot' / 'eboot.elf')} --app $in --flash_mode {esp8266_data[KEY_FLASH_MODE]} --flash_freq 40 --flash_size {_flash_size_str(BOARDS[board][KEY_FLASH_SIZE])} --path {_q(toolchain_bin)} --out $out",
         "  description = BIN $out",
         "rule copy",

tests/unit_tests/build_gen/test_arduino8266.py

@@ -1342,3 +1342,14 @@ def test_flash_ld_name_honors_ldscript_override(tmp_path: Path) -> None:
     CORE.platformio_options = {"board_build.ldscript": "../evil.ld"}
     with pytest.raises(EsphomeError, match="bare script name"):
         arduino8266._flash_ld_name("nodemcuv2")
+
+
+def test_write_project_quotes_spaced_ldscript_override(tmp_path: Path) -> None:
+    """An overridden script name re-quotes on the link line like every other
+    user token (a space would otherwise split into two argv elements)."""
+    CORE.platformio_options = {"board_build.ldscript": "my script.ld"}
+    paths = _make_framework(tmp_path)
+    _set_flags()
+    content = _write_ninja(paths)
+    assert "'my script.ld'" in content or '"my script.ld"' in content
+    assert "-T my script.ld" not in content