Bug: HTTP source cannot gain a verifier via PUT after noop creation, and provider field is not persisted (v26.7.6)

[MaggieT-creator]

Convoy v26.7.6 — two bugs in HTTP source verifier/provider handling

Bug 1: Cannot attach a verifier to a source created without one (HTTP PUT /sources)

Repro: POST a source with no verifier (type defaults to noop). Later PUT the same source
with verifier: {type: hmac, hmac: {...}} → HTTP 400 an error occurred while updating source.
Server log: failed to update source verifier ... source verifier not found.

Cause: internal/sources/impl.go (updateSource) only runs UPDATE on source_verifiers
and returns source verifier not found when RowsAffected() == 0 — there is no INSERT
branch when the source has no verifier row (noop-created sources have source_verifier_id NULL).

Workaround: seed the verifier row + link sources.source_verifier_id directly in SQL.

Expected: PUT should INSERT a verifier row when none exists (or the POST should persist
the verifier when supplied).

Bug 2: provider field silently not persisted via PUT source

Repro: PUT /sources/{uid} with "provider": "github" → 202 Source updated successfully,
response echoes the provider — but the provider column remains empty (verified via psql).

Impact: sources created without provider cannot gain provider-based verifiers
(NewGithubVerifier is only selected when source.Provider == github).

Expected: persist provider on update (or reject with a validation error).

Environment: Docker getconvoy/convoy:v26.7.6-amd64, Postgres 16, single project.

[linear]

PDE-1062