…17757)Used in combination withcoder/terraform-provider-coder#396This is required by both#17475 and#17571Operators may need to conditionalize their templates to perform certainoperations once a prebuilt workspace has been claimed. This value will**only** be set once a claim takes place and a subsequent `terraformapply` occurs. Any `terraform apply` runs thereafter will beindistinguishable from a normal run on a workspace.---------Signed-off-by: Danny Kopping <dannykopping@gmail.com>

Partially addressescoder/internal#593

This pull request allows coder workspace agents to be reinitialized whena prebuilt workspace is claimed by a user. This facilitates the transferof ownership between the anonymous prebuilds system user and the newowner of the workspace.Only a single agent per prebuilt workspace is supported for now, butplumbing has already been done to facilitate the seamless transition tomulti-agent support.---------Signed-off-by: Danny Kopping <dannykopping@gmail.com>Co-authored-by: Danny Kopping <dannykopping@gmail.com>Signed-off-by: Danny Kopping <dannykopping@gmail.com>

…17571)Closescoder/internal#369We can't know whether a replacement (i.e. drift of terraform stateleading to a resource needing to be deleted/recreated) will take placeapriori; we can only detect it at `plan` time, because the providerdecides whether a resource must be replaced and it cannot be inferredthrough static analysis of the template.**This is likely to be the most common gotcha with using prebuilds,since it requires a slight template modification to use prebuildseffectively**, so let's head this off before it's an issue forcustomers.Drift details will now be logged in the workspace build logs:![image](https://github.com/user-attachments/assets/da1988b6-2cbe-4a79-a3c5-ea29891f3d6f)Plus a notification will be sent to template admins when this situationarises:![image](https://github.com/user-attachments/assets/39d555b1-a262-4a3e-b529-03b9f23bf66a)A new metric - `coderd_prebuilt_workspaces_resource_replacements_total`- will also increment each time a workspace encounters replacements.We only track _that_ a resource replacement occurred, not how many. Justone is enough to ruin a prebuild, but we can't know apriori whichreplacement would cause this.For example, say we have 2 replacements: a `docker_container` and a`null_resource`; we don't know which one mightcause an issue (or indeed if either would), so we just track thereplacement.---------Signed-off-by: Danny Kopping <dannykopping@gmail.com>

We should only be tracking resource replacements during a prebuildclaim.Signed-off-by: Danny Kopping <dannykopping@gmail.com>

Also add some clarification about the lack of database constraints forsoft template deletion.---------Signed-off-by: Danny Kopping <dannykopping@gmail.com>Co-authored-by: Danny Kopping <dannykopping@gmail.com>

Signed-off-by: Danny Kopping <dannykopping@gmail.com>