Three new direct-lookup commands per v0.5.2-spec.md:
- ctask restore <ws> un-archive a workspace (metadata-only flip,
mirrors archive's lease guard, refuses to
restore an already-active workspace)
- ctask notes <ws> stream a workspace's notes.md to stdout (raw,
no framing, [ctask]-prefixed stderr on error)
so AI agents can read prior workspace context
through standard shell pipelines
- ctask path <ws> print the absolute filesystem path of a
workspace, OS-native separators, one line
All three resolve archived-inclusive: the user typed a name, so we
find the workspace whether or not it's archived. Listing stays
filtered (active-only by default) per the v0.5.2 design rule
"listing is filtered, direct lookup is comprehensive".
Adds shared completion infrastructure (cmd/completion.go) used by
these commands and wired into the existing workspace-accepting
commands in a follow-up commit. Candidates are workspace directory
basenames (e.g. 2026-04-22_promptvolley) rather than bare slugs
because basenames are unique under the resolver's exact-match step
while slugs can collide across categories or dates.
