Region- and tag-scoped WAF rules are armed on no node by default, silently, while list_waf_rules reports them enabled

`waf/waf.ts` builds `nodeIdentity` from `waf.region` and `waf.nodeTags`, and `static/defaultConfig.yaml:96` is literally `waf: {}` — neither key is set by default.

`isArmedOnNode` in `waf/matcher.ts` requires the node to satisfy every present selector:

```
if (activation.regions != null && (identity.region == null || !activation.regions.includes(identity.region))) return false;
```

So on a default install, any rule carrying `activation.regions` or `activation.tags` is armed on **zero** nodes. The rule is stored, `list_waf_rules` reports it as enabled, and `compileRules` drops it on the path that is documented as "compiled out silently — it's simply not-for-this-node, so it is neither invalid nor unsupported here". It appears in no invalid count, no unsupported count, and no log line.

That silence is what makes this worse than it first looks: an operator scoping a block rule to a region gets a rule that exists, reads as enabled, and protects nothing, with nothing anywhere reporting the gap.

**Suggested fix, in rough priority order:**

1. Report activation-gated rules in the compile summary as a third category (armed-elsewhere), so the count is visible per node.
2. Have `list_waf_rules` return armed/not-armed for the node answering the operation.
3. Decide what an unset `waf.region` should mean. Treating "no region configured" as "matches any region selector" trades a silent no-op for a silent over-match, so the reporting above probably has to land first either way.

Found by cross-model review while reviewing an unrelated change; not customer-reported. The WAF is unreleased — `main` and `v5.3.0-alpha.1` only.

Start with waf/waf.ts, waf/matcher.ts, and static/defaultConfig.yaml:96, then trace compileRules and list_waf_rules to understand how activation selectors affect reporting. Confirm the default configuration reproduces the silent no-node behavior; done means activation-gated rules are visibly distinguished from invalid and unsupported rules, with their armed status reported for the responding node.

Written by the indexing model from the issue text.