Fixes 8 cargo-doc warnings:
- hyperdht.rs:1168 broken link to connect_with_nodes -> Self::connect_with_nodes
- relay_service.rs module docs: 6 broken links (HyperDhtHandle, ServerEvent,
  BlindRelaySession, BlindRelayServer, UdxStream::relay_to, Io) fixed with
  fully-qualified paths
- io.rs:829 public doc on reply_to linked to a private item
  (Self::send_reply_deferred) -> reworded to prose/code-span, no longer a
  broken link

Expands module-level docs, previously thin/stale relative to the rapid
recent feature work:
- blind_relay.rs: explains the pairing/session model, idle-session-timeout
  hardening (peeroxide-only, no Node precedent), and stream teardown on
  unpair/session-close (1:1 Node precedent). Corrects a misleading claim
  that the relay is "unthrottled like Node" - peeroxide does impose its
  own configurable (generous-by-default) limits.
- relay_service.rs: documents the self-announce mechanism (announces
  hash(pubkey) to the DHT at startup plus a ~10min refresh so Node.js
  clients can discover the relay via findPeer), periodic idle-session and
  pairing sweep, and stream-teardown lifecycle.
- lib.rs: adds relay_service to the crate-level module overview table.

Documentation only, no behavior changes. cargo doc/clippy/test all clean.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

spawn()'s doc comment read like a basic direct/holepunched-only launcher
and didn't mention that a swarm can be configured to pair through a
blind-relay server via SwarmConfig::relay_through/relay_address. Crate-
level lib.rs docs updated similarly.

Documentation only, no behavior changes. cargo doc/clippy/test all clean.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…pdate README

Fixes 5 pre-existing cargo-doc warnings:
- chat/display.rs:87-88 [`render_to`] -> [`Self::render_to`]
- chat/tui/mod.rs:76 [`install_global`] -> [`super::install_global_notice_sink`]
- deaddrop/v2/keys.rs:6,8 array-index-style [i]/[0] misparsed as intra-doc
  links -> wrapped in code spans

Fixes a real, user-facing inaccuracy found while cross-checking a new
mdBook chapter against live --help output: `--idle-session-timeout` /
`--relay-idle-session-timeout` help text still claimed idle-session
sweeping was "not yet enforced" -- true when the flags were first added,
but stale since idle-session-timeout enforcement actually shipped in
peeroxide-dht 1.7.0 (sweep_idle_sessions is wired into run_relay_server's
periodic sweep task). Corrected in both relay.rs and node.rs.

README.md: adds the relay command to the command table (previously
omitted entirely), corrects the manpage count from 9 to 10 (verified by
actually running `peeroxide init --man-pages`), and clarifies that dd v2
is the current default protocol (--v1 opts into the legacy path).

Documentation only, no behavior changes. cargo doc/build/clippy all clean.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…ntent

Closes the biggest gap found in a full documentation audit: the
peeroxide node command and the entire blind-relay feature (peeroxide
relay, node --relay) had zero mdBook coverage anywhere, despite being
the focus of the last several development sessions.

Adds:
- docs/src/node/overview.md -- the peeroxide node command: what it does,
  basic/private-mesh/--relay usage, bootstrap resolution, flags.
- docs/src/relay/overview.md -- blind relay: what "blind" means, the two
  ways to run one (dedicated `relay` vs courtesy `node --relay`), all
  configurable limits/timeouts with real defaults, how clients opt in
  (SwarmConfig::relay_through/relay_address, PEEROXIDE_FORCE_RELAY for
  cp), and a security-notes section on what a relay can/cannot observe.
- docs/src/relay/architecture.md -- internals: token-pairing model, the
  Protomux "blind-relay" control channel, blind UDX-layer forwarding via
  relay_to, teardown/idle-timeout behavior (noting which parts have Node
  precedent and which are peeroxide-only hardening), and the relay
  self-announce mechanism for DHT discoverability.
- SUMMARY.md/introduction.md: wired both new chapters into navigation,
  corrected the primary-command count (eight -> nine).

Fixes:
- appendices/tracing.md: the relay row said logging was "(none
  currently)" -- stale, relay logging is now extensive. Replaced with
  the real tracing targets/events across relay.rs, node.rs,
  relay_service.rs, and blind_relay.rs.
- docs/src/node/overview.md's own idle-session-timeout flag description
  initially copied a stale "not yet enforced" claim from the CLI help
  text being fixed in the same pass -- corrected to match actual current
  behavior.
- docs/AGENTS.md: added node/ (and the general new-command-chapter
  convention covering relay/) to the structure notes; verified
  mdbook-mermaid is still genuinely needed (real diagram usage found in
  several existing chapters), left that instruction as-is.

mdbook build docs/ succeeds cleanly with no warnings.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>