refactor: compact PMM kernel headers below 5000 lines

[konard]

Fixes #360

Summary

• Compacts include/pmm/** from 6947 tracked lines to 4810 tracked lines, below the 5000-line blocking budget.
• Removes unreferenced include anchor comments while preserving linked and test-owned anchors.
• Folds wrapped header-only C++ declarations/statements into compact logical lines.
• Refreshes single_include/pmm/pmm.h from the canonical headers and aligns the repo-guard rollout checker with the 5000-line rule.
• Adds a patch changelog fragment.

Verification

• cmake -B build
• cmake --build build
• ctest --test-dir build --output-on-failure (94/94 passed)
• ctest --test-dir build --output-on-failure -R 'test_issue318_manager_header_compaction|test_issue352_kernel_subtree_size|test_issue354_include_anchors|test_issue306_repo_guard_gitkeep|test_issue358_release_workflow'
• scripts/check-docs-consistency.sh
• scripts/check-repo-guard-rollout.sh
• scripts/check-file-size.sh
• scripts/check-changelog-fragment.sh
• scripts/generate-single-headers.sh and temp-dir diff against single_include/pmm
• git ls-files 'include/pmm/**' | xargs wc -l | tail -1 -> 4810 total

Note: cppcheck is not installed in this container, so that optional local check was not run.

[konard]

Solution summary

Implemented and pushed to PR 362: #362

What changed:

• Reduced include/pmm/** from 6947 to 4810 tracked lines, below the 5000 budget.
• Preserved linked/test-owned include anchors.
• Refreshed single_include/pmm/pmm.h.
• Updated the repo-guard rollout checker to expect the 5000 limit.
• Added the changelog fragment and removed the placeholder .gitkeep.

Verification:

• Local cmake -B build, cmake --build build, and ctest --test-dir build --output-on-failure: 94/94 passed.
• Local repo checks passed: docs consistency, repo-guard rollout, file size, changelog fragment, single-header regeneration diff.
• Upstream CI is green for latest SHA aac65c7: https://github.com/netkeep80/PersistMemoryManager/actions/runs/24959459597

Working tree is clean.

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This summary was automatically extracted from the AI working session output.

[konard]

🤖 Solution Draft Log

This log file contains the complete execution trace of the AI solution draft process.

💰 Cost estimation:

• Model: GPT-5.5
• Provider: OpenAI
• Public pricing estimate: $29.906045

📊 Context and tokens usage:

• 25.8M / 1.1M (2457%) input tokens, 37.3K / 130K (29%) output tokens

Total: (269.4K + 25.5M cached) input tokens, 37.3K output tokens, $29.906045 cost

🤖 Models used:

• Tool: OpenAI Codex
• Requested: gpt-5.5
• Model: GPT-5.5 (gpt-5.5)

📎 Log file uploaded as Repository (48261KB)

• View complete solution draft log

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[konard]

✅ Ready to merge

This pull request is now ready to be merged:

• All CI checks have passed
• No merge conflicts
• No pending changes

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