Added

The documentation site now renders Mermaid diagrams. A ```mermaid fence is rewritten to a client-side renderer that follows the page theme, so the same fenced source renders on the site and on GitHub. Three seed diagrams are authored with it (the pieces and how they relate, the runtime data flow, and how npcap is acquired) on the Architecture page and in the master specification.

The Getting Started guide gains an annotated install walkthrough built from real Wireshark and Npcap installer screenshots, ending in a fragcap doctor verification step that shows the readiness output. Screenshots are served from site/public/screenshots/.

The Windows installer can now register fragcap as a Wireshark extcap capture source. An optional wizard step offers two opt-in choices, both off by default: register for the current user (the common case), or, for administrators, register for all users on the machine when Wireshark is detected. Both drive the existing fragcap extcap install command, a failed registration never fails the install, and leaving both unchecked registers nothing so you can run fragcap extcap install later. The choices are also public installer properties (REGISTEREXTCAP_USER, REGISTEREXTCAP_MACHINE) for silent installs.

fragcap doctor now points at where to get Wireshark. When the analyzer extcap integration is not registered, the guidance names the Wireshark download URL alongside fragcap extcap install, and notes that the Wireshark installer also provides npcap, so one download resolves both the recommended analyzer and the required capture driver. The URL is single-sourced in a new fragcap_core::interface::WIRESHARK_DOWNLOAD_URL constant, the sibling of DRIVER_DOWNLOAD_URL, and the npcap-absent remediation takes its Wireshark URL from the same constant rather than a second literal. doctor stays granular (the per-option npcap precision is unchanged) and the integration check remains a non-blocking optional warning; a ready environment's output is unchanged.

fragcap extcap install and fragcap extcap uninstall gained --user and --system scope flags. --user (the default when no scope is given) registers into the per-user Wireshark extcap directory; --system registers into the machine-wide one, resolving Wireshark's registry-recorded install directory (and falling back to the Program Files default), the same location doctor probes, so a machine-wide install and doctor agree even when Wireshark is installed outside Program Files. The existing --dir remains an explicit override, and the three selectors are mutually exclusive. This is the ergonomic form of what was previously only expressible by pointing --dir at the system directory; the default behavior is unchanged.

fragcap extcap install and fragcap extcap uninstall register and unregister fragcap as a Wireshark extcap capture source, so you no longer copy the binary into Wireshark's extcap directory by hand; fragcap doctor then reports the integration accordingly. Registration is per user, so on a shared machine each user who wants the Wireshark integration runs fragcap extcap install once; an administrator can register for the whole machine by pointing --dir at Wireshark's system extcap directory.