refactor(tools): fold research tools into :infrastructure:tools (drop new module)

The research feature is "no new architecture" (spec §1) — composition of existing
mechanisms. The only genuinely new code is the two web tools + the HTML→markdown
extractor (spec marks them "(new)"), and those belong with ShellTool/FileReadTool
in :infrastructure:tools, not in a separate module.

Moves extract/ + web/ from the short-lived :infrastructure:research module into
:infrastructure:tools (packages com.correx.infrastructure.tools.{extract,web}); adds
jsoup + ktor-client there; removes the module from settings.gradle. No behaviour change
— 44 tests green.

settings.gradle

@@ -39,7 +39,6 @@ include ':infrastructure:tools'
 include ':infrastructure:tools:filesystem'
 include ':infrastructure:workflow'
 include ':infrastructure:artifacts-cas'
-include ':infrastructure:research'
 
 include ':testing:replay'
 include ':testing:contracts'