Images linting: ensure that all images conform specification (#3802)

* Change all icons to be white background
* assets: re-processed all *.png images to 1-bit
* assets: also stripped profile data from .pngs
* assets: also stripped datetime from metadata (`-define png:exclude-chunks=date,time`)
* scripts: added image linter and formatter; fbt: added `lint_img` && `format_img` targets; github: integrated image lint step into CI
* scripts: imglint: fixed deprecation warning
* images: applied `format_img`
* fbt: added `lint_all` and `format_all` targets; docs: updated for new targets

Co-authored-by: hedger <hedger@nanode.su>
Co-authored-by: hedger <hedger@users.noreply.github.com>

.github/workflows/lint_and_submodule_check.yml

@@ -95,6 +95,22 @@ jobs:
             echo "C Lint: all good ✨" >> $GITHUB_STEP_SUMMARY;
           fi
 
+      - name: 'Check image assets'
+        if: always()
+        run: |
+          set +e;
+          ./fbt -s lint_img 2>&1 | tee lint-assets.log;
+          if [ "${PIPESTATUS[0]}" -ne 0 ]; then
+            # Save multiline output
+            echo "errors=1" >> $GITHUB_OUTPUT;
+            printf "Image Lint errors:\n\`\`\`\n" >> $GITHUB_STEP_SUMMARY;
+            echo "$(cat lint-assets.log)" >> $GITHUB_STEP_SUMMARY;
+            printf "\n\`\`\`\n" >> $GITHUB_STEP_SUMMARY;
+            exit 1;
+          else
+            echo "Image Lint: all good ✨" >> $GITHUB_STEP_SUMMARY;
+          fi
+
       - name: Report code formatting errors
         if: ( steps.syntax_check_py.outputs.errors || steps.syntax_check_cpp.outputs.errors ) && github.event.pull_request
         run: |

SConstruct

@@ -322,7 +322,12 @@ firmware_env.Append(
         "SConstruct",
         "firmware.scons",
         "fbt_options.py",
-    ]
+    ],
+    IMG_LINT_SOURCES=[
+        # Image assets
+        "applications",
+        "assets",
+    ],
 )
 
 
@@ -359,6 +364,39 @@ distenv.PhonyTarget(
     PY_LINT_SOURCES=firmware_env["PY_LINT_SOURCES"],
 )
 
+# Image assets linting
+distenv.PhonyTarget(
+    "lint_img",
+    [
+        [
+            "${PYTHON3}",
+            "${FBT_SCRIPT_DIR}/imglint.py",
+            "check",
+            "${IMG_LINT_SOURCES}",
+            "${ARGS}",
+        ]
+    ],
+    IMG_LINT_SOURCES=firmware_env["IMG_LINT_SOURCES"],
+)
+
+distenv.PhonyTarget(
+    "format_img",
+    [
+        [
+            "${PYTHON3}",
+            "${FBT_SCRIPT_DIR}/imglint.py",
+            "format",
+            "${IMG_LINT_SOURCES}",
+            "${ARGS}",
+        ]
+    ],
+    IMG_LINT_SOURCES=firmware_env["IMG_LINT_SOURCES"],
+)
+
+distenv.Alias("lint_all", ["lint", "lint_py", "lint_img"])
+distenv.Alias("format_all", ["format", "format_py", "format_img"])
+
+
 # Start Flipper CLI via PySerial's miniterm
 distenv.PhonyTarget(
     "cli",