Baseline moves to DSH 0.1.5-alpha.2 only (peer floor ^0.1.5-alpha.2,
CI pin, manifest engines); alpha.1 users stay on v0.19.0-alpha.0.
Host-contract changes handled:
- the native guide entry lost its `description` field (entries are
icon+title capsules now): `TabDescriptor.description` and the six
`guideDesc*` keys plus the `nativeGuideDesc` fallback are removed.
- the file address grammar changed: `fileAddressFor` always returns a
session-scoped address (absolute paths keep their leading `/`),
`parseFileAddress` is prefix-based and strips `?`/`#`. The plugin's
purity-gated mirror follows.
- global main panels replaced the `conversation` root slot with the
keyed `main` slot (`main.conversation`): the bottom workbench's
center-column locator now accepts both keys and skips
`display: contents` slot hosts.
Fixes a pre-existing fill bug the alpha.2 probe made obvious: the native
tab body host is a block scroller with a definite height, so tab roots
that only declared `flex: 1` collapsed to content height and the side
chat composer drifted off the pane bottom. The native adapter now wraps
every tab body in a `height: 100%` column flex host.
Also promotes the dependencies `dsh-client-ui-primitives@0.1.5-alpha.2`
dropped from its manifest (anser / shiki / mdast-util-* / micromark-* /
katex / @shikijs/langs) and the newly unmet `dsh-session-persistence`
peer into devDependencies.