Add defaults to calculations for ToolIO (#7289)

# Description of Changes
Currently when calculating the output file type for some tools, the
system will get it wrong because it doesn't know about what the default
parameters in tools are, so if it doesn't have a value for some key,
it'll just bail out and say "it might not be compatible". This PR adds
logic to `ToolIO` to read the default values set for the parameters if
the tool has `ToolIOCase`s and takes them into account when figuring out
the output type. I've built it with horrible Java reflection magic to
avoid having to specify the default for params twice, which will make it
impossible for the defaults to disagree with each other. This just runs
once at startup so there's negligible performance impact.

The change is easily tested with Change Parameters, which is just
`add-password` behind the scenes but with the password params omitted
(so Change Password is always PDF->PDF, never encrypted like Add
Password).

Also (somewhat hackily) fixes a bug I noticed where saving a Change
Permissions step then leaving and returning to the pipeline will cause
the step to be reloaded as Add Password. I've added a system to
disambiguate tools which share the same endpoint (which is only these
two currently).

## Currently

<img width="455" height="135" alt="image"
src="https://github.com/user-attachments/assets/c8867d6a-599b-4f21-a2db-4a1b6ac22d73"
/>

## Now

<img width="415" height="122" alt="image"
src="https://github.com/user-attachments/assets/bd8d1bab-f00a-421b-8c91-5af0d2ad5335"
/>

engine/scripts/generate_tool_models.py

@@ -65,6 +65,8 @@ class ToolIOWhen(ApiModel):
 
     param: str
     matches: list[str]
+    # The value the endpoint uses when this parameter is absent; None when it has none.
+    default: str | None = None
 
 
 class ToolIOCase(ApiModel):
@@ -378,7 +380,10 @@ def collect_tool_io(spec: dict[str, Any]) -> dict[str, dict[str, Any]]:
 
 
 def _render_when(condition: dict[str, Any]) -> str:
-    return f"ToolIOWhen(param={json.dumps(condition['param'])}, matches={json.dumps(condition['matches'])})"
+    parts = [f"param={json.dumps(condition['param'])}", f"matches={json.dumps(condition['matches'])}"]
+    if "default" in condition:
+        parts.append(f"default={json.dumps(condition['default'])}")
+    return f"ToolIOWhen({', '.join(parts)})"
 
 
 def _render_case(case: dict[str, Any]) -> str:

engine/src/stirling/models/tool_io.py

@@ -58,6 +58,8 @@ class ToolIOWhen(ApiModel):
 
     param: str
     matches: list[str]
+    # The value the endpoint uses when this parameter is absent; None when it has none.
+    default: str | None = None
 
 
 class ToolIOCase(ApiModel):
@@ -101,7 +103,7 @@ TOOL_IO: dict[ToolEndpoint, ToolIOSpec] = {
         arity=ToolArity.SIMO,
         cases=[
             ToolIOCase(
-                when=[ToolIOWhen(param="singleOrMultiple", matches=["single"])],
+                when=[ToolIOWhen(param="singleOrMultiple", matches=["single"], default="multiple")],
                 produces=ToolFormat.IMAGE,
                 arity=ToolArity.SISO,
             )
@@ -130,15 +132,19 @@ TOOL_IO: dict[ToolEndpoint, ToolIOSpec] = {
         arity=ToolArity.SISO,
         cases=[
             ToolIOCase(
-                when=[ToolIOWhen(param="outputFormat", matches=["ps"])],
+                when=[ToolIOWhen(param="outputFormat", matches=["ps"], default="eps")],
                 produces=ToolFormat.POSTSCRIPT,
                 arity=ToolArity.SISO,
             ),
             ToolIOCase(
-                when=[ToolIOWhen(param="outputFormat", matches=["pcl"])], produces=ToolFormat.PCL, arity=ToolArity.SISO
+                when=[ToolIOWhen(param="outputFormat", matches=["pcl"], default="eps")],
+                produces=ToolFormat.PCL,
+                arity=ToolArity.SISO,
             ),
             ToolIOCase(
-                when=[ToolIOWhen(param="outputFormat", matches=["xps"])], produces=ToolFormat.XPS, arity=ToolArity.SISO
+                when=[ToolIOWhen(param="outputFormat", matches=["xps"], default="eps")],
+                produces=ToolFormat.XPS,
+                arity=ToolArity.SISO,
             ),
         ],
     ),
@@ -151,7 +157,7 @@ TOOL_IO: dict[ToolEndpoint, ToolIOSpec] = {
         arity=ToolArity.MIMO,
         cases=[
             ToolIOCase(
-                when=[ToolIOWhen(param="combineIntoSinglePdf", matches=["true"])],
+                when=[ToolIOWhen(param="combineIntoSinglePdf", matches=["true"], default="false")],
                 produces=ToolFormat.PDF,
                 arity=ToolArity.MISO,
             )
@@ -202,7 +208,9 @@ TOOL_IO: dict[ToolEndpoint, ToolIOSpec] = {
         arity=ToolArity.SISO,
         cases=[
             ToolIOCase(
-                when=[ToolIOWhen(param="dryRun", matches=["true"])], produces=ToolFormat.JSON, arity=ToolArity.SISO
+                when=[ToolIOWhen(param="dryRun", matches=["true"], default="false")],
+                produces=ToolFormat.JSON,
+                arity=ToolArity.SISO,
             )
         ],
     ),
@@ -223,7 +231,9 @@ TOOL_IO: dict[ToolEndpoint, ToolIOSpec] = {
         arity=ToolArity.SISO,
         cases=[
             ToolIOCase(
-                when=[ToolIOWhen(param="sidecar", matches=["true"])], produces=ToolFormat.ZIP, arity=ToolArity.SISO
+                when=[ToolIOWhen(param="sidecar", matches=["true"], default="false")],
+                produces=ToolFormat.ZIP,
+                arity=ToolArity.SISO,
             )
         ],
     ),
@@ -242,7 +252,10 @@ TOOL_IO: dict[ToolEndpoint, ToolIOSpec] = {
         arity=ToolArity.SISO,
         cases=[
             ToolIOCase(
-                when=[ToolIOWhen(param="password", matches=[""]), ToolIOWhen(param="ownerPassword", matches=[""])],
+                when=[
+                    ToolIOWhen(param="password", matches=[""], default=""),
+                    ToolIOWhen(param="ownerPassword", matches=[""], default=""),
+                ],
                 produces=ToolFormat.PDF,
                 arity=ToolArity.SISO,
             )

engine/src/stirling/services/tool_io_compat.py

@@ -89,11 +89,16 @@ def resolve_output(spec: ToolIOSpec, parameters: dict[str, object] | None) -> Re
     for rule in spec.cases:
         all_hold = True
         for condition in rule.when:
-            if parameters is None or condition.param not in parameters:
+            if parameters is not None and condition.param in parameters:
+                raw: object = parameters[condition.param]
+            elif condition.default is not None:
+                # The caller omitted it, so it takes the endpoint's default.
+                raw = condition.default
+            else:
                 saw_unknown_param = True
                 all_hold = False
                 continue
-            normalised = _normalise(parameters[condition.param])
+            normalised = _normalise(raw)
             all_hold = all_hold and any(_normalise(m) == normalised for m in condition.matches)
         if all_hold:
             return ResolvedOutput(format=rule.produces, arity=rule.arity, certain=True)