feat(nomos): retry cap, vm: targets, inspect_path, goal supersession, runbooks

Session-review implementation for the three sessions audited in
plans/2026-07-18-session-review-three-sessions.md. v0.7.11 → v0.7.12.

P0.1 — retry cap + investigate-before-retry (cmd/nomos/retrycap.go,
agent.go): after 3 identical failing run calls in a single turn, refuse
to dispatch the call again and return a directive to investigate *why*
(ps/strace/lsof) or surface the blocker. Per-turn scope so a fresh turn
after the operator responds can retry once more. Session 1e9c7691's 20+
identical chown retries (knfsd held a kernel lock on the exported NFS
dir) is the direct motivation.

P0.2 + P1.8 + P2.10 — SOUL.md guidance: hung command is not a failed
command (investigate before retry); ask before proposing a multi-step
migration; multi-goal sessions summarize the arc not just the last goal.

P1.3 — two new runbook entities in seeds/knowledge.yaml:
  - nfs-exported-dir-mutation-hang (the knfsd fchownat lock procedure:
    killall → exportfs -u → mutate → exportfs -a → verify)
  - netbird-mgmt-oidc-race-after-upgrade (docker restart netbird-mgmt
    after ~30s for the traefik/authentik OIDC race)

P1.4 — setGoal emits task.superseded event when prior goal is overwritten
by a different goal (store.go, TestSetGoal_SupersededEvent). Session
55927f0a had two set_goal calls with the first silently abandoned.

P1.5 — inspect_path MCP tool: runs mount/df/ls/stat for one path across
up to 8 targets in one parallel call, replacing the 15+ run-call
fact-gathering fan-out sessions 1 and 2 each spent on cross-target path
tracing (tools.go, server.go: inspectPathAcrossTargets, inspectOneTarget).

P1.6 — vm: target support in run via qm guest exec (no more SSH-hop
with nested quoting). Extracted shared resolveProxmoxHostSlug for
LXC + VM, with hosts-relationship fallback when attributes.host is
absent (server.go, tools.go). Session 55927f0a's SSH-hop workarounds
for vm:zimaos are the direct motivation.

Deferred (documented in plan): P1.7 (approval window auto-extend on
timeout) and P2.9 (long-running command PENDING detection) — both
addressed at lower cost by the retry cap. Session 3's poll-after-timeout
pattern already works; the cap protects against the failure mode.

internal/mcp/tools.go

@@ -314,9 +314,9 @@ func allTools(pool *db.Pool, agentID uuid.UUID) []toolReg {
 		// for future runbook extraction — especially pct_create DNS/VMID logic.
 		// DO NOT re-register this tool. See plans/2026-07-10-general-gated-execution.md.
 
-		{tool: &mcp.Tool{Name: "run", Description: "Run ANY shell command against any host or LXC. This is the general execution primitive — prefer it over asking the operator to run something manually, and don't wait for a matching fixed action to exist. Every command is automatically risk-classified: read-only inspection (cat, systemctl status, docker ps, journalctl, df, git status, ...) runs immediately; anything that changes state requires operator approval (granted by the operator replying \"go ahead\"/\"yes\" in chat, or via the Approve button); commands matching a destructive pattern (rm -rf, dd, mkfs, pct/qm destroy, DROP TABLE, reboot, piping curl into a shell, ...) always require approval regardless of what you declare. You cannot talk your way past the destructive check by declaring a lower risk.",
+		{tool: &mcp.Tool{Name: "run", Description: "Run ANY shell command against any host, LXC, or VM. This is the general execution primitive — prefer it over asking the operator to run something manually, and don't wait for a matching fixed action to exist. Every command is automatically risk-classified: read-only inspection (cat, systemctl status, docker ps, journalctl, df, git status, ...) runs immediately; anything that changes state requires operator approval (granted by the operator replying \"go ahead\"/\"yes\" in chat, or via the Approve button); commands matching a destructive pattern (rm -rf, dd, mkfs, pct/qm destroy, DROP TABLE, reboot, piping curl into a shell, ...) always require approval regardless of what you declare. You cannot talk your way past the destructive check by declaring a lower risk.",
 			InputSchema: objSchema(
-				prop{"target", "string", "Target entity slug: host:<slug> (e.g. host:strong) or lxc:<slug> (e.g. lxc:caddy). LXC commands run via pct exec on its Proxmox host automatically."},
+				prop{"target", "string", "Target entity slug: host:<slug> (e.g. host:strong), lxc:<slug> (e.g. lxc:caddy), or vm:<slug> (e.g. vm:zimaos). LXC commands run via pct exec on their Proxmox host automatically. VM commands run via qm guest exec on their Proxmox host (requires the QEMU guest agent inside the VM — standard for Proxmox VMs)."},
 				prop{"command", "string", "The shell command to run. Can be a full script (multi-line, &&-chained). Runs as root."},
 				prop{"purpose", "string", "One sentence: why you're running this. Shown to the operator alongside the approval — be specific, this is what they're approving."},
 				prop{"declared_risk", "string", "Optional self-assessment: read_only, reversible_low, config_mutation, or destructive. This can only ESCALATE the automatic classification, never lower it — declaring a mutating command as read_only has no effect."},
@@ -340,6 +340,44 @@ func allTools(pool *db.Pool, agentID uuid.UUID) []toolReg {
 			return classifyAndGate(ctx, pool, agentID, targetID, targetSlug, command, purpose, declaredRisk, sessionID), nil
 		}},
 
+		// inspect_path is the bulk fact-gathering tool from
+		// plans/2026-07-18-session-review-three-sessions.md P1.5.
+		// Sessions 1e9c7691 and 55927f0a each spent ~15 `run` calls
+		// gathering identical facts (`mount | grep`, `df`, `ls -la`,
+		// `stat`) across hosts and LXCs to understand where a path
+		// lives, who mounts it, and what permissions it has. This tool
+		// collapses that fan-out into one call: pass a path and a list
+		// of targets, get back per-target mount/df/ls/stat output as
+		// JSON. All commands are read-only, so no approval is needed.
+		{tool: &mcp.Tool{Name: "inspect_path", Description: "Bulk fact-gathering: run mount/df/ls/stat for the same path across multiple host/LXC/VM targets in ONE call. Returns a JSON object keyed by target slug, each with the target's view of the path (mount source, filesystem, size, top-level entries with ownership/permissions). Use this instead of N separate `run` calls when you need to understand a path's footprint across the fleet (e.g. tracing where a volume is mounted, checking permissions on the same NFS path from server + client). All commands are read-only — no approval needed.",
+			InputSchema: objSchema(
+				prop{"path", "string", "Absolute path to inspect on each target (e.g. /mnt/media_local, /media/ludo-library)."},
+				prop{"targets", "array", "List of target entity slugs (host:strong, lxc:nfs-export, vm:zimaos, …). Up to 8 per call."},
+			),
+		}, handler: func(ctx context.Context, req *mcp.CallToolRequest) (*mcp.CallToolResult, error) {
+			args := argsMap(req)
+			path, _ := args["path"].(string)
+			if path == "" {
+				return textResult("error: path is required"), nil
+			}
+			rawTargets, _ := args["targets"].([]any)
+			if len(rawTargets) == 0 {
+				return textResult("error: at least one target is required"), nil
+			}
+			if len(rawTargets) > 8 {
+				return textResult("error: at most 8 targets per inspect_path call (use two calls if you need more)"), nil
+			}
+			targets := make([]string, 0, len(rawTargets))
+			for _, t := range rawTargets {
+				if s, ok := t.(string); ok && s != "" {
+					targets = append(targets, s)
+				}
+			}
+			results := inspectPathAcrossTargets(ctx, pool, path, targets)
+			out, _ := json.MarshalIndent(results, "", "  ")
+			return textResult(string(out)), nil
+		}},
+
 		{tool: &mcp.Tool{Name: "http_get", Description: "Fetch a public web page or raw file (e.g. a GitHub README/raw URL) and return sanitized text. Use this to research how to deploy a service before provisioning. HTTP/HTTPS only; body is truncated to ~16KB.",
 			InputSchema: objSchema(
 				prop{"url", "string", "Absolute http(s) URL to fetch"},