chore(structure): split hook modules into role-specific files

[RonnyPfannschmidt]

Review PR — step 1 of 7.

This PR targets the previous step's branch, so its diff is only this step's change. Review happens here. The corresponding upstream PR, which is the one that actually merges, is pytest-dev#703.

Merges happen upstream one step at a time, bottom-up. When step 1 lands upstream, this PR is closed and the rest of the stack is rebased onto the new main.

Step	Branch	Review (downstream)	Merge (upstream)
1	refactor/split-hook-modules	#6	pytest-dev#703 ←
2	refactor/configuration-objects	#5	pytest-dev#704
3	refactor/markers-attach-config	#7	pytest-dev#706
4	refactor/hookimpl-wrapper-types	#8	pytest-dev#707
5	refactor/hookcaller-and-execution	#9	pytest-dev#708
6	refactor/project-spec	#10	pytest-dev#709
7	refactor/async-submitter	#11	pytest-dev#710

Chain step 01 of the internal-refactoring series (see design/ docs, added in step 02's branch).

Splits _hooks.py into role-specific modules (_config, _decorators, _caller, _implementation, _execution) with _hooks.py kept as a compat re-export layer.

Part of the stacked chain: each PR in this chain targets the previous step's branch so it shows only its own diff. The full-diff PRs against pytest-dev/pluggy link back here.

🤖 Generated with Claude Code

Summary by Sourcery

Split the monolithic internal hooks module into role-specific modules while preserving backward-compatible re-exports.

Enhancements:

• Factor hook specification/implementation configuration types into a dedicated _config module.
• Extract hook markers, specifications, and helper utilities into a new _decorators module.
• Extract hook caller and relay logic into a new _caller module.
• Extract hook implementation representation into a new _implementation module.
• Extract multicall execution and wrapper teardown handling into a new _execution module.
• Update _hooks and _callers to act as thin compatibility layers that re-export symbols from the new modules.

[sourcery-ai]

Reviewer's Guide

Refactors pluggy’s internal hook machinery into role-specific modules while preserving the original public surface via re-export shims for backward compatibility.

File-Level Changes

Change	Details	Files
Split monolithic _hooks.py into role-focused modules and turn _hooks.py into a compatibility re-export layer.	Remove inlined hook types, markers, caller, spec, and implementation classes from _hooks.py. Introduce new modules for configuration, decorators/specs, callers/relay, implementations, and execution. Update _hooks.py to import from the new modules and define a consolidated all for the legacy import path.	src/pluggy/_hooks.py src/pluggy/_config.py src/pluggy/_decorators.py src/pluggy/_caller.py src/pluggy/_implementation.py src/pluggy/_execution.py
Extract hook execution (multicall and wrapper machinery) into a dedicated _execution module and keep _callers.py as a thin re-export shim.	Move Teardown type alias, run_old_style_hookwrapper, _raise_wrapfail, _warn_teardown_exception, and _multicall into _execution.py. Simplify _callers.py to import the execution helpers from _execution and re-export them via all. Preserve existing behaviour and signatures while only changing where functionality lives.	src/pluggy/_callers.py src/pluggy/_execution.py

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[sourcery-ai]

Hey - I've found 1 issue

Prompt for AI Agents

Please address the comments from this code review:

## Individual Comments

### Comment 1
<location path="src/pluggy/_caller.py" line_range="271" />
<code_context>
+    """A proxy to another HookCaller which manages calls to all registered
+    plugins except the ones from remove_plugins."""
+
+    # This class is unusual: in inhertits from `HookCaller` so all of
+    # the *code* runs in the class, but it delegates all underlying *data*
+    # to the original HookCaller.
</code_context>
<issue_to_address>
**nitpick (typo):** Fix typo in comment: "inhertits" should be "inherits".

Please fix the spelling here so the comment remains clear for future maintainers, given it documents a subtle design choice.

```suggestion
    # This class is unusual: it inherits from `HookCaller` so all of
```
</issue_to_address>

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[sourcery-ai]

nitpick (typo): Fix typo in comment: "inhertits" should be "inherits".

Please fix the spelling here so the comment remains clear for future maintainers, given it documents a subtle design choice.

Suggested change

	# This class is unusual: in inhertits from `HookCaller` so all of
	# This class is unusual: it inherits from `HookCaller` so all of