Add edit text support to stirling engine (#6245)

# Description of Changes
Hooks up the (alpha) PDF Editor backend to the AI engine Edit Agent via
an intermediary API which is easier for the agent to call. It suffers
from all the same issues that the PDF Editor does in actually editing
the text, but should also benefit from any fixes to that.

It also adds protection against the underlying tools misbehaving by
hanging, and fixes a hanging bug in the PDF Editor.

---------

Co-authored-by: EthanHealy01 <[email protected]>

engine/src/stirling/models/tool_models.py

@@ -373,6 +373,25 @@ class EditTableOfContentsParams(ApiModel):
     )
 
 
+class EditTextOperation(ApiModel):
+    find: str = Field(..., description="The literal text to find.")
+    replace: str = Field(..., description="The replacement text. May be empty to delete the matched text.")
+
+
+class EditTextParams(ApiModel):
+    edits: list[EditTextOperation] | None = Field(
+        None,
+        description="Ordered list of find/replace operations. Each replaces every occurrence on the selected pages, in order; later operations see the result of earlier ones (so 'foo'->'foos' then 'foos'->'bars' turns 'foo' into 'bars').",
+    )
+    page_numbers: str | None = Field(
+        "all",
+        description="The pages to select, Supports ranges (e.g., '1,3,5-9'), or 'all' or functions in the format 'an+b' where 'a' is the multiplier of the page number 'n', and 'b' is a constant (e.g., '2n+1', '3n', '6n-5')",
+    )
+    whole_word_search: bool | None = Field(
+        False, description="Whether matches must be whole words (boundaries determined by non-word characters)"
+    )
+
+
 class EmlToPdfParams(ApiModel):
     download_html: bool | None = Field(
         None, description="Download HTML intermediate file instead of PDF", examples=[False]
@@ -1105,6 +1124,7 @@ class Model(
         | BookletImpositionParams
         | CropParams
         | EditTableOfContentsParams
+        | EditTextParams
         | MergePdfsParams
         | MultiPageLayoutParams
         | OverlayPdfsParams
@@ -1172,6 +1192,7 @@ class Model(
         | BookletImpositionParams
         | CropParams
         | EditTableOfContentsParams
+        | EditTextParams
         | MergePdfsParams
         | MultiPageLayoutParams
         | OverlayPdfsParams
@@ -1240,6 +1261,7 @@ type ParamToolModel = (
     | BookletImpositionParams
     | CropParams
     | EditTableOfContentsParams
+    | EditTextParams
     | MergePdfsParams
     | MultiPageLayoutParams
     | OverlayPdfsParams
@@ -1309,6 +1331,7 @@ class ToolEndpoint(StrEnum):
     BOOKLET_IMPOSITION = "/api/v1/general/booklet-imposition"
     CROP = "/api/v1/general/crop"
     EDIT_TABLE_OF_CONTENTS = "/api/v1/general/edit-table-of-contents"
+    EDIT_TEXT = "/api/v1/general/edit-text"
     MERGE_PDFS = "/api/v1/general/merge-pdfs"
     MULTI_PAGE_LAYOUT = "/api/v1/general/multi-page-layout"
     OVERLAY_PDFS = "/api/v1/general/overlay-pdfs"
@@ -1376,6 +1399,7 @@ OPERATIONS: dict[ToolEndpoint, ParamToolModelType] = {
     ToolEndpoint.BOOKLET_IMPOSITION: BookletImpositionParams,
     ToolEndpoint.CROP: CropParams,
     ToolEndpoint.EDIT_TABLE_OF_CONTENTS: EditTableOfContentsParams,
+    ToolEndpoint.EDIT_TEXT: EditTextParams,
     ToolEndpoint.MERGE_PDFS: MergePdfsParams,
     ToolEndpoint.MULTI_PAGE_LAYOUT: MultiPageLayoutParams,
     ToolEndpoint.OVERLAY_PDFS: OverlayPdfsParams,