SFT-3834: removed unused security_menu and sign_text_file_flow

diff --git a/ports/stm32/boards/Passport/manifest.py b/ports/stm32/boards/Passport/manifest.py
index ee1ddb5..b3ab807 100644
--- a/ports/stm32/boards/Passport/manifest.py
+++ b/ports/stm32/boards/Passport/manifest.py
@@ -151,7 +151,6 @@ freeze('$(MPY_DIR)/ports/stm32/boards/Passport/modules',
         'flows/sign_psbt_common_flow.py',
         'flows/sign_psbt_microsd_flow.py',
         'flows/sign_psbt_qr_flow.py',
-        'flows/sign_text_file_flow.py',
         'flows/temporary_seed_flow.py',
         'flows/terms_of_use_flow.py',
         'flows/update_firmware_flow.py',
diff --git a/ports/stm32/boards/Passport/modules/flows/__init__.py b/ports/stm32/boards/Passport/modules/flows/__init__.py
index dc94e86..767b466 100644
--- a/ports/stm32/boards/Passport/modules/flows/__init__.py
+++ b/ports/stm32/boards/Passport/modules/flows/__init__.py
@@ -67,7 +67,6 @@ from .set_chain_flow import *
 from .set_initial_pin_flow import *
 from .show_security_words_setting_flow import *
 from .sign_electrum_message_flow import *
-from .sign_text_file_flow import *
 from .sign_psbt_common_flow import *
 from .sign_psbt_microsd_flow import *
 from .sign_psbt_qr_flow import *
diff --git a/ports/stm32/boards/Passport/modules/flows/sign_text_file_flow.py b/ports/stm32/boards/Passport/modules/flows/sign_text_file_flow.py
deleted file mode 100644
index 0c600e4..0000000
--- a/ports/stm32/boards/Passport/modules/flows/sign_text_file_flow.py
+++ /dev/null
@@ -1,112 +0,0 @@
-# SPDX-FileCopyrightText: © 2022 Foundation Devices, Inc. <hello@foundation.xyz>
-# SPDX-License-Identifier: GPL-3.0-or-later
-#
-# sign_text_file_flow.py - Ask user to choose a file from microSD and then sign it.
-
-from files import CardMissingError, CardSlot
-from flows import Flow, FilePickerFlow
-from pages import SuccessPage, ErrorPage, InsertMicroSDPage
-from tasks import sign_text_file_task
-from utils import spinner_task, validate_sign_text
-from translations import t, T
-from public_constants import AF_CLASSIC, MSG_SIGNING_MAX_LENGTH, RFC_SIGNATURE_TEMPLATE
-import sys
-
-
-def is_signable(filename, path=None):
-    # print('is_signable: {}'.format(filename))
-    if '-signed' in filename.lower():
-        return False
-
-    return True
-    # with open(filename, 'rt') as fd:
-    #     lines = fd.readlines()
-    #     print('len(lines) = {}'.format(len(lines)))
-    #     return (1 <= len(lines) <= 5)
-
-
-class SignTextFileFlow(Flow):
-    def __init__(self):
-        super().__init__(initial_state=self.select_file, name='SignTextFileFlow')
-
-    async def select_file(self):
-        result = await FilePickerFlow(filter_fn=is_signable, show_folders=True).run()
-        if result is None:
-            self.set_result(False)
-            return
-
-        _filename, full_path, is_folder = result
-        if not is_folder:
-            self.file_path = full_path
-            self.goto(self.validate_file)
-
-    async def validate_file(self):
-        from common import system
-
-        with CardSlot() as card:
-            with open(self.file_path, 'rb') as fd:
-                import os
-
-                s = os.stat(self.file_path)
-                self.size = s[6]
-
-                # Check length
-                if self.size < 2:
-                    await ErrorPage(
-                        'File is too short. Must be at least 2 bytes.'.format(MSG_SIGNING_MAX_LENGTH)).show()
-                    self.set_result(False)
-                    return
-
-                if self.size > MSG_SIGNING_MAX_LENGTH:
-                    await ErrorPage(
-                        'File is too long. Max. length is {} bytes.'.format(MSG_SIGNING_MAX_LENGTH)).show()
-                    self.set_result(False)
-                    return
-
-                # Read the file
-                self.text = fd.readline().strip().decode('utf-8')
-
-                self.subpath = fd.readline().strip().decode('utf-8')
-
-                # Validate
-                (subpath, error) = validate_sign_text(self.text, self.subpath)
-                if error is not None:
-                    await ErrorPage(text=error).show()
-                    self.set_result(False)
-                    return
-
-                self.subpath = subpath
-
-                # All looks good so far, so try to sign it
-                self.goto(self.do_sign)
-
-    async def do_sign(self):
-        (signature, address, error) = await spinner_task('Signing File', sign_text_file_task,
-                                                         args=[self.text, self.subpath, AF_CLASSIC])
-        if error is None:
-            self.signature = signature
-            self.address = address
-            self.goto(self.write_signed_file)
-        else:
-            # TODO: Refactor this to a simpler, common error handler page?
-            await ErrorPage(text='Error while signing file: {}'.format(error)).show()
-            self.set_result(False)
-            return
-
-    async def write_signed_file(self):
-        # complete. write out result
-        from ubinascii import b2a_base64
-        from flows import SaveToMicroSDFlow
-        from public_constants import RFC_SIGNATURE_TEMPLATE
-
-        orig_path, basename = self.file_path.rsplit('/', 1)
-        base, ext = basename.rsplit('.', 1)
-        filename = base + '-signed' + '.' + ext
-        sig = b2a_base64(self.signature).decode('ascii').strip()
-        data = RFC_SIGNATURE_TEMPLATE.format(addr=self.address, msg=self.text, blockchain='BITCOIN', sig=sig)
-        result = await SaveToMicroSDFlow(filename=filename,
-                                         data=data,
-                                         success_text="signed file",
-                                         path=orig_path,
-                                         mode='t').run()
-        self.set_result(result)
diff --git a/ports/stm32/boards/Passport/modules/menus.py b/ports/stm32/boards/Passport/modules/menus.py
index cbb1d40..cf3c1a8 100644
--- a/ports/stm32/boards/Passport/modules/menus.py
+++ b/ports/stm32/boards/Passport/modules/menus.py
@@ -317,18 +317,6 @@ def bitcoin_menu():
     ]
 
 
-def security_menu():
-    from flows import ChangePINFlow, SignTextFileFlow, NewSeedFlow, RestoreSeedFlow
-
-    return [
-        {'icon': 'ICON_SEED', 'label': 'Restore Seed', 'flow': RestoreSeedFlow, 'is_visible': lambda: not has_seed(),
-         'args': {'refresh_cards_when_done': True}},
-        {'icon': 'ICON_SEED', 'label': 'New Seed', 'flow': NewSeedFlow, 'is_visible': lambda: not has_seed(),
-         'args': {'refresh_cards_when_done': True}},
-        {'icon': 'ICON_SIGN', 'label': 'Sign Text File', 'flow': SignTextFileFlow, 'is_visible': has_seed},
-    ]
-
-
 def update_menu():
     from flows import UpdateFirmwareFlow, ViewCurrentFirmwareFlow
     from utils import is_logged_in