control: replace afp_client with afpc namespaces

[rdmark]

Introduce the afpc control client as the single entry point for discovery, stateless-log operations, and FUSE mount management. FUSE commands now live under the fs namespace and afpsld commands under sl, providing unambiguous command ownership and clearer diagnostics for missing namespaces.

Retain mount_afpfs as an AFP-URL compatibility symlink command by dispatching it through afpc, while removing the afp_client command which was previously a symlink to mount_afpfs with a different invocation mode.

Update Meson integration so afpc is available regardless of FUSE support, with filesystem-specific command handling compiled only when FUSE is enabled.

Harden controller IPC writes and response framing, including bounded response handling and exact command matching.

Refresh manuals and project documentation for the new syntax, and add parser/invocation coverage alongside the existing discovery and FUSE test updates.

[augmentcode]

🤖 Augment PR Summary

Summary: This PR replaces the legacy afp_client compatibility entrypoint with a new unified afpc control client that dispatches explicit namespaces for discovery, FUSE mount control, and stateless-log operations.

Changes:

• Introduces control/afpc as the primary dispatcher with discover, sl, and (when built) fs namespaces
• Moves former FUSE-control commands under afpc fs and stateless-controller commands under afpc sl
• Retains mount_afpfs as an AFP-URL compatibility symlink that routes to afpc; removes the old afp_client symlink
• Refactors Meson build wiring so afpc is built regardless of FUSE support, with FS-specific code linked only in FUSE builds
• Hardens controller IPC by adding full-write helpers, readable-waiting, and bounded response framing in the FUSE client
• Updates manpages/docs to the new syntax and removes the old afp_client(1) page
• Adds/updates tests for invocation-name dispatch and updated discovery/FUSE command expectations

Technical Notes: The FS command implementation is now exposed as afpc_fs_command()/afpc_mount_url_command() and linked into afpc only when FUSE is enabled; discovery remains available in all builds.

_{🤖 Was this summary useful? React with 👍 or 👎}

[augmentcode]

Review completed. 3 suggestions posted.

Comment augment review to trigger a new review at any time.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[rdmark]

@andylemin this is ready for review, see the readmes and man pages for descriptions of the new usage patterns

the one thing I'm on the fence about is whether to introduce symlink aliases for afpc fs -> afpfs and afpc sl -> afpsl -- I like the symmetry of afpfs controlling afpfsd and afpsl controlling afpsld but it does clutter the namespace a bit and requires us to ship man pages for two additional commands

what do you think?

[andylemin]

This is great! This makes me very happy and avoids stress on the little finger by not having to type _ 😁

[rdmark]

agreed, it's much more typable... only drawback is that afpcmd is not as convenient to type anymore with tab completion