Bring 6 upstream PR ports onto upstream-fixes

docs/syntax.md

@@ -85,6 +85,9 @@ tweak:  # optional tweaking of .gv output
   # loops
   loops: <List>  # every list item is itself a list of exactly two pins
                  # on the connector that are to be shorted
+
+  # optional tweaking of .gv output executed for each instance of this connector
+  tweak:  # see tweak section below
 ```
 
 ## Cable attributes
@@ -148,6 +151,8 @@ tweak:  # optional tweaking of .gv output
   show_wirecount: <bool>    # defaults to true
   show_wirenumbers: <bool>  # defaults to true for cables; false for bundles
 
+  # optional tweaking of .gv output executed for each instance of this cable
+  tweak:  # see tweak section below
 ```
 
 ## Connection sets
@@ -393,6 +398,11 @@ See [HTML Output Templates](../src/wireviz/templates/) for how metadata entries
 
   # Character to split template and designator for autogenerated components
   template_separator: <str>    # Default = '.'
+
+  # Graphviz dpi attribute (https://graphviz.org/docs/attrs/dpi/).
+  # Controls the resolution of raster (PNG) output and the size unit of
+  # vector (SVG) output.
+  output_dpi: <float>          # Default = 96.0
 ```
 
 
@@ -452,6 +462,12 @@ Alternatively items can be added to just the BOM by putting them in the section
   # This feature is experimental and might change
   # or be removed in future versions.
 
+  placeholder: <str>  # Substring to be replaced with the node name in
+    # any per-connector / per-cable tweak overrides and append entries.
+    # An empty string disables placeholder substitution for that node.
+    # When omitted at the per-node level, the global placeholder
+    # (in the top-level tweak: section) is used as the fallback.
+
   override:  # dict of .gv entries to override
     # Each entry is identified by its leading string
     # in lines beginning with a TAB character.

src/wireviz/DataClasses.py

@@ -59,6 +59,12 @@ class Options:
     color_mode: ColorMode = "SHORT"
     mini_bom_mode: bool = True
     template_separator: str = "."
+    # Graphviz dpi attribute (https://graphviz.org/docs/attrs/dpi/) — controls
+    # the resolution of raster (PNG) output and the size unit of vector (SVG)
+    # output. Default 96.0 matches Graphviz's default for non-PostScript
+    # output. Set to ``null`` in YAML (``None`` in Python) to omit the dpi
+    # attribute entirely and let Graphviz pick its renderer-specific default.
+    output_dpi: Optional[float] = 96.0
 
     def __post_init__(self):
         if not self.bgcolor_node:
@@ -73,6 +79,7 @@ def __post_init__(self):
 
 @dataclass
 class Tweak:
+    placeholder: Optional[PlainText] = None
     override: Optional[Dict[Designator, Dict[str, Optional[str]]]] = None
     append: Union[str, List[str], None] = None
 
@@ -164,10 +171,13 @@ class Connector:
     loops: List[List[Pin]] = field(default_factory=list)
     ignore_in_bom: bool = False
     additional_components: List[AdditionalComponent] = field(default_factory=list)
+    tweak: Optional[Tweak] = None
 
     def __post_init__(self) -> None:
         if isinstance(self.image, dict):
             self.image = Image(**self.image)
+        if isinstance(self.tweak, dict):
+            self.tweak = Tweak(**self.tweak)
 
         self.ports_left = False
         self.ports_right = False
@@ -329,10 +339,13 @@ class Cable:
     show_wirenumbers: Optional[bool] = None
     ignore_in_bom: bool = False
     additional_components: List[AdditionalComponent] = field(default_factory=list)
+    tweak: Optional[Tweak] = None
 
     def __post_init__(self) -> None:
         if isinstance(self.image, dict):
             self.image = Image(**self.image)
+        if isinstance(self.tweak, dict):
+            self.tweak = Tweak(**self.tweak)
 
         if isinstance(self.gauge, str):  # gauge and unit specified
             try: