* docs: bring doc titles and descriptions into SEO length limits
Rewrite the frontmatter title and description of every published doc so the
rendered <title> lands in 50-60 characters (including the site suffix) and the
meta description lands in 150-160 characters.
* docs: move SEO titles to a seoTitle field and restore display titles
The frontmatter title renders as the page H1 and the sidebar label, so tuning it
for the title tag shortened nothing and lengthened the visible navigation. Put
the search-facing string in seoTitle and give title back its original value.
Merges `feat/ebs-export-tunables` (83 commits) into dev. The branch could not be rebase-merged because it carries five merges from dev, so it lands as a squash.
## What is in it
- **EBS export tunables** and the nbdkit/viperblock export path they configure.
- **Teardown reapers and backoff** for S3 buckets, load balancers, gateways, spot requests, certificates, endpoints, elastic IPs and network interfaces, so a dependent that keeps failing is backed off rather than retried hot.
- **Retry and tolerance paths**: ECS IAM service init, ECR signing keys deleted between the list and the read, an unreadable signing key at awsgw startup, and an ECS instance-profile policy attach converging on a stale read.
- **Key pair validation reads the material by name** instead of listing the account, closing the `InvalidKeyPair.NotFound` race that a single-replica LIST could produce.
- **Concurrency and fan-out**: concurrent metadata document fetches, bounded metadata reads for describes, and the node-discovery timeout removed from every fan-out call.
- **OVN correctness against the configured NB cluster**: the flows barrier, nexthop MAC binding, and stopping a compute node from running the package's standalone database.
- **nats-js-watchdog can re-arm itself.** The escalation check ran above the probe loop while the only line that cleared the counter sat below it, so a latched watchdog could never observe a recovery. It now probes first and decides second, and says so once per latch rather than once per tick.
- **CI**: 19 commits of nightly and build-pipeline work.
## Verification
`make preflight` green locally. Build and Test, Integration Tests, Race Detection, and Lint and Security all green on `c2da0385`.
## Known red, not introduced here
Two nightly cells fail on this branch and are pre-existing:
- **cell-10** — a partial OVN IPsec enable leaves `NB_Global ipsec=true` asserted cluster-wide while two of three chassis failed their local reconcile, black-holing cross-chassis guest traffic for roughly 5.5 minutes while every health signal stays green.
- **cell-19** — a total layer-3 egress blackhole below a correctly and promptly programmed NAT/EIP datapath, aggravated by a natuplink probe whose retry budget outlives the test's own wait, so it can never emit its FAIL verdict.
Both are filed separately and should be weighed before a release is cut.
Josh Siviour