docs: record harvest v3 creds for local setup

Author: nathanclairmonte

AGENTS.md

@@ -99,7 +99,7 @@ djlint templates/path/to/file.html --lint --profile=jinja   # djlint for html/ji
 | Service       | Purpose                          | Key Env Vars |
 | ------------- | -------------------------------- | ------------ |
 | Discourse API | Blog, takeovers, docs, tutorials | `DISCOURSE_API_KEY`, `DISCOURSE_API_USERNAME`, `MAAS_DISCOURSE_API_KEY`, `MAAS_DISCOURSE_API_USERNAME` |
-| Careers       | Careers related                  | `HARVEST_API_KEY`, `APPLICATION_CRYPTO_SECRET_KEY` |
+| Careers       | Careers related                  | `HARVEST_V3_CLIENT_ID`, `HARVEST_V3_CLIENT_SECRET`, `APPLICATION_CRYPTO_SECRET_KEY` |
 | Greenhouse    | Candidate applications           | `GREENHOUSE_API_KEY` |
 | Google Calendar | Google Calendar service-account auth             | `SERVICE_ACCOUNT_EMAIL`, `SERVICE_ACCOUNT_PRIVATE_KEY` |
 | Marketo       | Marketing / lead gen             | `MARKETO_API_URL`, `MARKETO_API_CLIENT`, `MARKETO_API_SECRET` |
@@ -126,4 +126,4 @@ djlint templates/path/to/file.html --lint --profile=jinja   # djlint for html/ji
 ## Docs
 
 - `README.md` — project overview, setup, development workflow, and common commands
-- `AGENTS.md` — instructions and conventions for AI agents/contributors working in the repository
+- `AGENTS.md` — instructions and conventions for AI agents/contributors working in the repository

README.md

@@ -40,7 +40,7 @@ Environment variables are read from the available shell. For the charm, these ar
 
 ## Greenhouse API
 
-To work locally on the `/careers` section of the site, you will need to add a `HARVEST_API_KEY` environment variable to `.env` file. You can find this via the [Greenhouse admin panel](https://canonical.greenhouse.io/configure/dev_center/credentials).
+To work locally on the `/careers` section of the site, add `HARVEST_V3_CLIENT_ID` and `HARVEST_V3_CLIENT_SECRET` environment variables to your `.env.local` file.
 
 # Deploy