Merge branch 'master' into next

Forward-merge the v0.4.0 pre-release content (dependency refresh, CI
deb-install + AUR-build legs, docs refresh, doc-comment fixes, and the
Phase 4 source-content squash: CHANGELOG, release notes, README,
fips.yaml, Cargo.toml metadata, reference docs) up the one-way flow.

Conflict fixups (keep next's identity, fold in master's improvements):
- Version: keep next's 0.5.0-dev (Cargo.toml/lock).
- README status: keep next's v0.5.0-dev / wire-format-breaking framing
  and the Breaking-section pointer; fold in the Nym transport and the
  "global, public test mesh of thousands of nodes" description.
- docs/reference/cli-fips.md: keep next's 0.5.0-dev version example.
- CHANGELOG: keep next's XX-handshake admission entry (no early cap gate
  on XX) and drop master's IK early-cap-at-handle_msg1 entry, which
  describes IK-only behavior that does not apply on next; take master's
  OR-union mesh-size rewrite (next carries the OR-union code); restore
  the Tor connect_refused and MMP receiver-report entries that the
  Fixed-section consolidation would otherwise have dropped.
- lifecycle.rs: keep the mDNS/LAN handshake doc-comment as Noise XX
  (next unifies on XX), not master's XX-to-IK correction.

Quartet green on the merged tree: fmt, build, clippy -D warnings, and
cargo test --lib (1434 passed).

docs/tutorials/host-a-service.md

@@ -98,11 +98,10 @@ is what you want.
 Or via the daemon:
 
 ```sh
-sudo fipsctl show identities
+sudo fipsctl show status
 ```
 
-The first JSON entry has `local: true` and a `ula` field — that
-is your address.
+The JSON has an `ipv6_addr` field — that is your address.
 
 For the rest of this tutorial we will write the address as
 `<your-fips0-addr>`. Substitute the actual `fd97:...` value

docs/tutorials/ipv6-adapter-walkthrough.md

@@ -63,9 +63,11 @@ mesh address:
 dig npub1qmc3cvfz0yu2hx96nq3gp55zdan2qclealn7xshgr448d3nh6lks7zel98.fips AAAA +short
 ```
 
-You should see one AAAA record returning a `fd97:...` address.
-The prefix is the FIPS ULA range (`fd00::/8`, with `fd97:...`
-covering the address space derived from npubs).
+You should see one AAAA record returning an address such as
+`fd97:...`. The prefix is the FIPS ULA range (`fd00::/8`): only
+the leading `fd` byte is fixed, and everything after it is hash
+output derived from the npub, so the digits beyond `fd` vary per
+node.
 
 The query went through `systemd-resolved` (or your platform
 equivalent), which routed `.fips` queries to the daemon's local

docs/tutorials/reach-mesh-services.md

@@ -56,8 +56,11 @@ hostname on the public internet. There is no separate
 the tool takes a hostname, it accepts a `.fips` hostname.
 
 > **Where the address comes from.** Every FIPS node's mesh
-> address is the SHA-256 of its public key, truncated to the
-> bottom 64 bits and prepended with `fd97:`. Names of the form
+> address is the first 16 bytes of SHA-256 of its public key,
+> with the leading byte replaced by `0xfd` (the `fd00::/8` ULA
+> prefix). The remaining bytes are hash output, so an address
+> like `fd97:...` is per-node — the `97` is part of the hash,
+> not a fixed prefix shared across nodes. Names of the form
 > `<npub>.fips` and any shortname mapped in `/etc/fips/hosts`
 > are aliases for that address. The daemon's local DNS
 > responder hands the answer back to your kernel without ever