feat(missions): Continuous Research is a mission type, not just a team checkbox

`templates/teams/continuous_research.toml` has existed with three well-written
roles since it was authored, but no workflow recipe pointed at it — every
recipe in templates/workflows/ defaults `default_team_template = "rust_sdlc"`.
So the only way to reach it was as a checkbox under Advanced. It is now a
Step-1 card: the registry loads it at boot and `GET /api/workflows` serves it,
with no frontend change (MissionWizard renders whatever the endpoint returns).

Both phases are kind `research`, deliberately, rather than new `read`/`script`
kinds. An unrecognised kind falls through `purposes_for`'s `_ => ["mission"]`
and is absent from `PRODUCING_KINDS`, so it would get the generic directive AND
be exempt from the empty-delivery rule — a phase that produces nothing and
still passes. That is the shape this codebase keeps paying for; two `research`
phases differentiated by `task` keep both guards.

`commit_policy = "always"`, not `on_green_tests`: the vault is prose with no
suite, so a test gate would find nothing to run and land every branch `-wip`.

The harvest is NOT an agent phase. `continuous_research.rs` calls the existing
`library::run_to_vault` — arXiv search, seen-set check, PDF shelf, vault note,
attributed by `mission_id` — because that path is deterministic, takes seconds,
and owns the `corpus_items` seen-set that is the whole reason a recurring
mission knows what it already covered. An agent redoing it would be slower and
would lose that.

The manifest path is not invented either: the team template has told
`signal_harvester` to write `ContinuousResearch/<date>/harvest.jsonl` all along.
This makes the code produce what the prompt already promised, and a test pins
the path and every documented key so the two cannot drift into an agent reading
a file nothing writes.

DEFAULT_CORPUS / DEFAULT_VAULT_URL exported rather than duplicated, so the
route and the launch hook cannot disagree about which vault.

344 tests pass.

Co-Authored-By: Claude Opus 5 <[email protected]>

crates/cm-api/src/lib.rs

@@ -24,6 +24,7 @@ mod mcp_skills;
 pub mod microvm_client;
 pub mod microvm_executor;
 pub mod microvm_turn_executor;
+pub mod continuous_research;
 pub mod mission_delivery;
 pub mod mission_events;
 pub mod mission_fs;