Add docs/ (SPECIFICATION, ROADMAP, OPERATIONS, COMMAND_REFERENCE,
THREAT_MODEL) describing the current v0.7 agent and the phased path from
local HIDS to a host security platform. Reframe README, package metadata,
and CLI/module descriptions from "intrusion-detection daemon" to "Linux
host security platform", and surface the v0.7 signed-package verify
(pkgdb_pkgverify*) and anti-rootkit (rootcheck_*) knobs in the sample
config. Also wrap the pacman.conf read in pkgdb.siglevel_alert in a
context manager to avoid a leaked file handle.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>