docs: delete stale hard-cut roadmap; add state durability/recovery map

[TraderSamwise]

Why

docs/runtime-core-hard-cut-roadmap.md was an unmaintained, AI-generated aspirational doc. Its "Current Cut Line" asserted "Backend session ids for exact resume live in topology session records" — a claim the code disproved, and which masked the capture regression that this whole series of PRs fixed. It is not a tracked WIP roadmap. Stale docs that lie are worse than no docs.

Change

• Delete the roadmap (recoverable from git history if ever needed).
• Add docs/state-durability-and-recovery.md: a short, code- and test-anchored map of the invariants landed in W0–W3 — durable atomic+fsync writes, quarantine-on-corrupt, backend-id capture, and backend-id recovery — each pointing at the test that enforces it (the test is the contract; the doc is the map). Also houses the deferred CLI-hierarchy proposal, explicitly marked as needing sign-off.
• Repoint the one dangling inbound link in runtime-authority-inventory.md.

No code changes. No remaining references to the deleted file.

🤖 Generated with Claude Code

Summary by CodeRabbit

Release Notes

• Documentation
  • Improved documentation on runtime authority tracking with clarified references to validation documentation
  • Added comprehensive documentation on state durability, crash recovery procedures, and data integrity safeguards
  • Removed obsolete roadmap documentation to streamline project guidance

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Project	Deployment	Actions	Updated (UTC)
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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: d2b6fba5-f7e1-4f91-b6ee-846bac0327ea

📥 Commits

Reviewing files that changed from the base of the PR and between e7aaad3 and 9fc97ed.

📒 Files selected for processing (3)

• docs/runtime-authority-inventory.md
• docs/runtime-core-hard-cut-roadmap.md
• docs/state-durability-and-recovery.md

💤 Files with no reviewable changes (1)

• docs/runtime-core-hard-cut-roadmap.md

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📝 Walkthrough

Walkthrough

This PR introduces comprehensive documentation of state durability and crash recovery, then clarifies the runtime authority inventory's role in tracking authoritative state. The changes establish durable persistence invariants, corruption handling, and recovery flows as core concepts, removing redundant roadmap documentation in the process.

Changes

State Durability and Authority Documentation

Layer / File(s)	Summary
State Durability and Recovery Framework docs/state-durability-and-recovery.md	Introduces new documentation defining authority topology as the source of truth, durable write invariants (atomic staging + fsync + rename + directory fsync), corruption visibility (quarantine torn files instead of overwriting), backend session ID capture via HTTP hooks and post-crash recovery from on-disk session stores, the aimux repair recovery command, and a note on proposed CLI hierarchy restructuring requiring explicit sign-off.
Runtime Authority Inventory Clarification docs/runtime-authority-inventory.md	Adds introductory text clarifying that the inventory tracks a concrete authority map per domain and directing readers to the state durability, corruption handling, and backend ID recovery documentation for durable-write validation.

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Possibly related PRs

• TraderSamwise/aimux#38: Documentation updates to the same runtime authority inventory and hard-cut roadmap files, with overlapping changes to durability invariants and roadmap content.
• TraderSamwise/aimux#29: Initial creation of the runtime authority inventory and hard-cut roadmap docs that this PR now clarifies and reorganizes.
• TraderSamwise/aimux#34: Earlier updates to runtime authority inventory and hard-cut roadmap addressing authority/projection boundaries that this PR builds upon.

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Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

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Poem

📚 A rabbit's tale of durable dreams,
Where state flows clean through recovery streams,
Authority maps keep truth held tight,
While quarantine guards corruption's bite—
Durability codified, one doc at a time! 🔧

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main changes: deleting a stale roadmap file and adding new documentation on state durability/recovery, matching the core content of the changeset.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch chore/docs-cleanup-state-authority

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