Allow network commands to select stored names

Leaving a configured network required copying its opaque id even when its
name identified exactly one saved network. Resolve exact, case-sensitive
names from the existing local state alongside full ids and unique id prefixes.
Use the shared resolver for leave, stop, start, secret and broadcast so the
same selector has the same meaning throughout the CLI. IPC and storage still
operate on the resolved id; release and offline-removal behavior are unchanged.

Refuse ambiguous names and name/id-prefix collisions before any mutation,
listing matching names and full ids without secrets. Full ids take precedence
to provide a definitive escape from ambiguity. Preserve copied id ellipses
without stripping literal ellipses from network names.

Update help and examples. Make administrator-friendly, predictable CLI behavior
a core requirement in AGENTS.md, including actionable errors and no guessing
which resource a destructive command should affect.

Validation on Windows: cargo fmt --all -- --check and workspace/all-target
Clippy with -D warnings passed. Release workspace/all-target tests: 318 passed,
including real-process online/offline leave-by-name, preservation of other
networks, ambiguous/unknown selectors, and consistent name selection across
commands. Two existing Windows SQLite wipe failures were explicitly skipped
(a_wipe_removes_everything_and_the_next_start_is_a_stranger and
wiping_twice_is_as_ordinary_as_wiping_once). The public-DHT smoke test and
forwarding benchmark remain ignored by default. Tests use isolated state;
the user's running agent and configured networks were not changed.

README.md

@@ -362,11 +362,11 @@ tsunagi id key rotate           replace that key
 tsunagi network                 the networks this device belongs to
 tsunagi network join -n lab -s tsn1…   join one; adds it to a running agent
 tsunagi network join -n lab     resume one this device has, or make it on the spot
-tsunagi network stop <id>       stop serving it, keeping everything
-tsunagi network start <id>      serve it again, from where it left off
-tsunagi network leave <id>      give up the address and name, then forget it
+tsunagi network stop lab        stop serving it, keeping everything
+tsunagi network start lab       serve it again, from where it left off
+tsunagi network leave lab       give up the address and name, then forget it
 tsunagi network secret          the secret of each joined network
-tsunagi network secret <id>     just that one, for copying
+tsunagi network secret lab      just that one, for copying
 tsunagi network secret generate a fresh secret for a network that does not exist yet
 
 tsunagi dns                     whether the local resolver is serving, and what
@@ -599,8 +599,8 @@ received broadcasts never trigger another fanout.
 ```sh
 tsunagi join -n games --no-broadcast
 tsunagi join -n games --broadcast
-tsunagi network broadcast <network-id-or-prefix> off
-tsunagi network broadcast <network-id-or-prefix> on
+tsunagi network broadcast games off
+tsunagi network broadcast games on
 ```
 
 The choice persists across restarts and a plain `join`. It can be changed while
@@ -674,7 +674,7 @@ Membership outlives a session, so it also has to be possible to end it.
 
 ```bash
 tsunagi network                     # what this device belongs to
-tsunagi network leave <network-id>  # give up the address and the name, then forget it
+tsunagi network leave lab           # give up the address and the name, then forget it
 tsunagi wipe --yes                  # remove everything and be a stranger again
 ```
 
@@ -703,9 +703,12 @@ nothing can sign or send it: the command says so and refuses, and `--offline`
 drops the network locally while leaving the others holding the old claim. The
 protocol key for that network goes too — rejoining is joining, not resuming.
 
-A network is named by its id, never by its name: two networks can share a
-name, and choosing between them for the user is how the wrong one gets left. A
-unique prefix is enough.
+`leave`, `stop`, `start`, `secret` and `broadcast` accept an exact stored network
+name, its full id, or a unique id prefix (including a copied report ellipsis).
+Names are case-sensitive. If several networks share a name, or a name matches
+another network's id prefix, the command lists matching names and full ids and
+changes nothing. Use a full id to choose explicitly; a full id always takes
+precedence over a name. No secret is needed to select a configured network.
 
 `wipe` removes both directories' contents: the device identity, every network,
 every signed record and everything a protocol kept beside them. It refuses