docs(j5): peering docs match the shipped behavior

[Jacksondr5]

Problem

Several J5 peering docs had drifted from what the code does, as Bryant's review of the poll-mode stack (#400, #407, #408) and CodeRabbit found. Closes #487, part of #399.

What changed

Docs only. Each claim was checked against the code.

• docs/j5/product/cross-device.md:
  • The address book measures availability only for a peer server that polls this one. For any other link mode, availabilityOf returns null.
  • A message sent directly to a server that is off fails after a few quick retries, as the user guide says, instead of being "lost".
• docs/j5/runbooks/peering.md: when peer remove cancels messages, it names who gets which notice:
  • a message the peer may already hold says it may not have been delivered;
  • an ask, or a message on an Exchange the removal drops, is told by that Exchange's drop notice;
  • a sender already told of a refusal gets nothing more.
• docs/j5/product/a2a/agent-tools.md: "the sender is told", not "the message is told".
• Name refresh: a renamed server's name reaches the other one when either server polls the other or reads the other's address book. That is fixed in the user guide and in the runbook's two "each time they talk" lines.
• docs/README.md: links the peering guide next to the other J5 user guides.

Left out, as ruled: AC13's wording about revoked sessions. #486's 2b.2 decides how peer sessions are revoked, so that wording changes with it.

Upstream impact

• docs/README.md gains one link line. It is recorded in FORK.md case 48 (case text, and the file-table row is now 42, 45, 48).

Checklist

• One concern: the description has no "also"
• Tests cover the changed behavior: no behavior changes, docs only
• UI changes: none
• Upstream-owned files: docs/README.md is recorded in FORK.md case 48, in the case text and the file-table row
• Upstream product: unchanged
• Surfaces: docs only. The marketing explainer was checked for the same claims and needs no change
• Docs: the definitions in cross-device.md and agent-tools.md, the runbook, and the user guide are rewritten in place

Claude Opus 5.5 (1M context), in J5 Code through the Claude Code harness.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Documentation
  • Added a guide for connecting two J5 servers, accessible from the documentation home page.
  • Clarified that messages sent to an offline server may fail after a few retries, and that a message marked as not delivered may already have reached the peer.
  • Updated guidance on when server names refresh and when peer availability appears in the address book.
  • Clarified what senders can expect when a peer is removed, including cases where no separate not-delivered notice is sent.

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Project	Deployment	Actions	Updated
j5-code	Ready	Preview	Oct 8, 2026 10:36am UTC

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ℹ️ Recent review info

⚙️ Run configuration

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📥 Commits

Reviewing files that changed from the base of the PR and between 4b17291 and 2e196db.

📒 Files selected for processing (1)

• docs/j5/runbooks/peering.md

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📝 Walkthrough

Walkthrough

Peering documentation now links to the user guide and describes integration case 48. It clarifies when server names refresh, how availability is reported for polling peers, and what delivery and removal notices describe.

Changes

J5 peering documentation

Layer / File(s)	Summary
Guide entry points and name refresh FORK.md, docs/README.md, docs/user/j5-peering.md, docs/j5/runbooks/peering.md	Adds integration case 48 to the documentation inventory, links the peering guide, and specifies when a server name refreshes.
Delivery, availability, and removal notices docs/j5/product/a2a/agent-tools.md, docs/j5/product/cross-device.md, docs/j5/runbooks/peering.md	Clarifies offline-server delivery, availability for polling peers, potentially held messages, and the notices associated with peer removal.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Other

Merge Risk: ⚪ Minimal · up to 2e196

The updated guide accurately explains delivery retries, polling-peer availability, and who receives removal notices. No material documentation mismatch remains, so this docs-only change is ready to merge.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Linked Issues check	⚠️ Warning	Issue #487 requirements for availability, direct-send retries, removal notices, sender wording, name refresh, and the docs/README.md link are represented in the reported documentation changes. Howev…	Update AC13 in docs/j5/product/cross-device.md to the revoked-session behavior decided for #486 before merging, or update the linked issue requirements if #487 is formally changed.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies a documentation update that aligns J5 peering documentation with shipped behavior.
Description check	✅ Passed	The description follows the required template, explains the documentation problems and changes, records upstream impact, addresses UI and testing scope, completes the checklist, and identifies the mod…
Out of Scope Changes check	✅ Passed	The reported changes are limited to J5 peering documentation, the required docs/README.md guide link, and the FORK.md record for that upstream-owned documentation change. These changes support the…
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…

Full details: Linked Issues check

Explanation

Issue #487 requirements for availability, direct-send retries, removal notices, sender wording, name refresh, and the docs/README.md link are represented in the reported documentation changes. However, #487 also requires AC13 revoked-session wording to be revised. docs/j5/product/cross-device.md still states that a revoked session shows the peer server without a live session on the issuer's record. The PR description says this requirement is deferred to #486, but that deferral does not remove the open direct issue requirement.

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[coderabbitai]

Actionable comments posted: 1

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• 🪄 Fix CodeRabbit comments on this PR

🤖 Prompt to fix review comments

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Inline comments:
Review comments at @docs/j5/runbooks/peering.md:
- Line 66: Update the `j5 a2a peer remove` documentation so it identifies the
sender as the recipient of the Exchange drop notice for an ask or a message on
an Exchange dropped by removal.

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ℹ️ Review info

⚙️ Run configuration

• Configuration used: Repository: Jacksondr5/j5code/.coderabbit.yaml
• Review profile: CHILL
• Plan: Essentials
• Run ID: 3c0b3c80-7b25-492d-8d37-752d26339e35

📥 Commits

Reviewing files that changed from the base of the PR and between 284f85b and 4b17291.

📒 Files selected for processing (6)

• FORK.md
• docs/README.md
• docs/j5/product/a2a/agent-tools.md
• docs/j5/product/cross-device.md
• docs/j5/runbooks/peering.md
• docs/user/j5-peering.md

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