docs: fix Markdown links breaking README refresh CI

[kapustazh]

Summary

The README refresh in #148 is already merged. CI rejects two bare links in its
session context record. Format the email as inline code and the PR URL as a
Markdown link. Record the failure and successful repository-wide validation.

This is a new PR; #148 is left untouched.

Scope and acceptance criteria

• Limited to the session context Markdown fix.
• CI's exact Markdown command passes across all 213 files.
• No unrelated cleanup or runtime changes.

Product and security invariants

• Tenant isolation remains fail-closed.
• Sponsor authorization, auditability, and daily caps remain enforced where applicable.
• Recipients cannot modify sponsor controls or access sponsor-only data.
• No secrets or sensitive runtime configuration included.
• Non-applicable invariants explained below.

Invariant notes: documentation formatting only; no runtime or payment changes.
The public contact email is owner-authorized.

Validation

npx --yes markdownlint-cli2@0.18.1 '**/*.md' '#node_modules': PASS, 213 files, zero errors
git diff --check origin/develop HEAD: PASS

Independent review evidence

Gate A — exact candidate tree before push

• Verdict: SKIPPED at owner's explicit instruction to omit FreePi for this work.
• No PASS claimed.

Gate B — exact remote PR head

• Verdict: SKIPPED at the same instruction.
• CI: pending at creation; draft PR.

Risk and rollback

• Residual risks: no behavior changes; remote CI pending.
• Rollback: revert the single documentation commit.

Human merge

• A human owner has reviewed the evidence and will perform the merge.