feat: claim prebuilds based on workspace parameters instead of preset id (#19279)

Closes https://github.com/coder/coder/issues/18356.

This change finds and selects a matching preset if one was not chosen
during workspace creation. This solidifies the relationship between
presets and parameters.

When a workspace is created without in explicitly chosen preset, it will
now still be eligible to claim a prebuilt workspace if one is available.

coderd/database/queries/prebuilds.sql

@@ -245,3 +245,30 @@ INNER JOIN organizations o ON o.id = w.organization_id
 WHERE NOT t.deleted AND wpb.build_number = 1
 GROUP BY t.name, tvp.name, o.name
 ORDER BY t.name, tvp.name, o.name;
+
+-- name: FindMatchingPresetID :one
+-- FindMatchingPresetID finds a preset ID that is the largest exact subset of the provided parameters.
+-- It returns the preset ID if a match is found, or NULL if no match is found.
+-- The query finds presets where all preset parameters are present in the provided parameters,
+-- and returns the preset with the most parameters (largest subset).
+WITH provided_params AS (
+	SELECT
+		unnest(@parameter_names::text[]) AS name,
+		unnest(@parameter_values::text[]) AS value
+),
+preset_matches AS (
+	SELECT
+		tvp.id AS template_version_preset_id,
+		COALESCE(COUNT(tvpp.name), 0) AS total_preset_params,
+		COALESCE(COUNT(pp.name), 0) AS matching_params
+	FROM template_version_presets tvp
+	LEFT JOIN template_version_preset_parameters tvpp ON tvpp.template_version_preset_id = tvp.id
+	LEFT JOIN provided_params pp ON pp.name = tvpp.name AND pp.value = tvpp.value
+	WHERE tvp.template_version_id = @template_version_id
+	GROUP BY tvp.id
+)
+SELECT pm.template_version_preset_id
+FROM preset_matches pm
+WHERE pm.total_preset_params = pm.matching_params  -- All preset parameters must match
+ORDER BY pm.total_preset_params DESC               -- Return the preset with the most parameters
+LIMIT 1;