Rewrite the cacert unit suite for the TenantProjection model: the
happy-path projection, the Ready=False/SourceNotFound status a missing
source now surfaces, ownership solely by the sentinel, the write-path
guards driven through a real source (private key and non-certificate
refused), the canonical-name cases, and the forged-projection heal. The
pure write-path guard tests — including the DER-reassembly guarantee —
carry over unchanged.
Replace the cacert chainsaw suite: it probes the writer policy against
the live API server (RBAC denies a tenant, the VAP denies a
non-flux writer, flux is allowed) and drives the controller end to end
(a flux-created sentinel reports SourceNotFound, then lifts a real CA
into a key-free, sentinel-owned projection). Drop the declared-leg
wiring test.
Signed-off-by: Aleksei Sviridkin <f@lex.la>