Linux VM page cache (#1270): QEMU VM memory now falls back to Proxmox
RRD's memavailable metric (which excludes reclaimable page cache) when
the qemu-guest-agent doesn't provide MemInfo.Available. Previously the
fallback was detailedStatus.Mem (total - MemFree), inflating usage to
80%+ on VMs with normal Linux page cache. Mirrors the existing LXC
rrd-memavailable path.
FreeBSD ZFS ARC (#1264, #1051): The host agent now reads
kstat.zfs.misc.arcstats.size via SysctlRaw on FreeBSD and subtracts
the ARC size from reported memory usage. ZFS ARC is reclaimable under
memory pressure (like Linux SReclaimable) but gopsutil counts it as
wired/non-reclaimable, causing false 90%+ memory alerts on TrueNAS
and FreeBSD hosts. Build-tagged so it compiles cleanly on all platforms.
Fixes#1270Fixes#1264Fixes#1051
(cherry picked from commit 94502f83ff9ffc6da28aaadc946a2f7d8b4e9bac)
Resolves two remaining TODOs from codebase audit.
## 1. PBS/PMG Test Harness Stubs
**Location:** internal/monitoring/harness_integration.go:149-151
**Changes:**
- Added PBS client stub registration: `monitor.pbsClients[inst.Name] = &pbs.Client{}`
- Added PMG client stub registration: `monitor.pmgClients[inst.Name] = &pmg.Client{}`
- Added imports for pkg/pbs and pkg/pmg
**Purpose:**
Enables integration test scenarios to include PBS and PMG instance types
alongside existing PVE support. Stubs allow scheduler to register and
execute tasks for these instance types during integration testing.
**Testing:**
✅ TestAdaptiveSchedulerIntegration passes (55.5s)
✅ Integration test harness now supports all three instance types
## 2. HTTP Config URL Fetch
**Location:** cmd/pulse/config.go:226-261
**Problem:**
`PULSE_INIT_CONFIG_URL` was recognized but not implemented, returning
"URL import not yet implemented" error.
**Implementation:**
- URL validation (http/https schemes only)
- HTTP client with 15 second timeout
- Status code validation (2xx required)
- Empty response detection
- Base64 decoding with fallback to raw data
- Matches existing env-var behavior for `PULSE_INIT_CONFIG_DATA`
**Security:**
- Both HTTP and HTTPS supported (HTTPS recommended for production)
- URL scheme validation prevents file:// or other protocols
- Timeout prevents hanging on unresponsive servers
**Usage:**
```bash
export PULSE_INIT_CONFIG_URL="https://config-server/encrypted-config"
export PULSE_INIT_CONFIG_PASSPHRASE="secret"
pulse config auto-import
```
**Testing:**
✅ Code compiles cleanly
✅ Follows same pattern as existing PULSE_INIT_CONFIG_DATA handling
## Impact
- Completes integration test infrastructure for all instance types
- Enables automated config distribution via HTTP(S) for container deployments
- Removes last TODOs from codebase (no TODO/FIXME remaining in Go files)
