fix(sync): restore the empty params table for a Build image

[cplieger]

A Deployment with a Build image whose build is unset serializes to TOML that Komodo cannot read back, so every later read of the sync file fails. Same failure class as #1581, reached without any name/id confusion.

The bug

Deployment::edit_config_object renames build_id to build and removes version when it is 0.0.0, which the entity documents as meaning latest. If the build is also unset, no keys remain, skip_empty_object drops the whole params table, and DeploymentImage is adjacently tagged (tag = "type", content = "params"), so this cannot be deserialized:

image.type = "Build"

TOML parse error at line 1, column 1
missing field `params`

Tests in this PR cover all three states: the empty table is dropped and fails to parse, restoring it round trips, and a populated image is unaffected.

Precedent

This file already works around the identical hazard twice, both with comments:

• Builder::push_additional appends a literal params = {} because "toml_pretty will remove empty map but in this case its needed to deserialize the enums".
• The Procedure stage serializer passes TOML_PRETTY_OPTIONS.skip_empty_object(false) because "If the execution.params are fully missing, deserialization will fail".

The nested image case was missed. The first commit follows the Builder precedent, one level deeper: image.params = {}.

Two ways to reach it

Build unset. validate_config does not require a non-empty build_id for a Build image, so a Deployment in that state is constructible and its export is already unreadable.

A dangling reference. ReplaceIds blanked build_id when the Build lookup missed, which is the common route into the state above. The lookup misses whenever the reference is dangling, and a dangling reference is the normal outcome here: deleting a resource clears permissions, recently-viewed and alerter targets via delete_from_alerters, but nothing clears a Deployment's build_id. Build::pre_delete is empty and post_delete only drops a build_state_cache entry.

The second commit stops that blanking. It is not the parse fix, and I have kept it separate on purpose: its value is that it no longer overwrites a reference the user committed to a git-tracked file with an empty string, matching the change made for ResourceTarget ids in #1581. It does not make a dangling reference resolve; it makes it legible instead of blank. Drop that commit if you would rather keep blanking.

Deliberately not included

The sibling lookups in ReplaceIds (server_id, swarm_id, linked_repo, builder_id, and the two server_ids vectors) blank the same way. They do not break parsing, because those fields carry #[serde(default)] and an empty string is valid TOML, so I have left them alone rather than send a dozen unrequested edits. They do still erase a committed reference. Happy to follow up if you want them consistent.

Verification

cargo check -p komodo_core clean, cargo fmt --check clean, the three new tests pass. bin/core had no test module before this, so tell me if you would rather these lived elsewhere or not at all.