[text-auditor] Batch fix clear grammar/typo issues in user-facing field docs and CI messages

## Text Improvements

The following user-facing text issues were found in the repository. Each is a low-effort fix.

### 1. Missing verb in `Destination dn` field description family

**Current text:** `An X.500 (LDAP) Distinguished name that used in a context that indicates a Destination dn`

**Suggested fix:** `An X.500 (LDAP) Distinguished name that is used in a context that indicates a destination DN`

**Why:** Clear grammar error (`that used` missing `is`), repeated across multiple user-visible field/docs tables.

**Verified occurrences:**
- `packages/fortinet_forticlient/data_stream/log/fields/fields.yml` (line 1432)
- `packages/juniper_junos/data_stream/log/fields/fields.yml` (line 1432)
- `packages/bluecoat/data_stream/director/fields/fields.yml` (line 1432)
- `packages/netscout/data_stream/sightline/fields/fields.yml` (line 1432)
- `packages/radware/data_stream/defensepro/fields/fields.yml` (line 1432)
- `packages/tomcat/data_stream/log/fields/fields.yml` (line 1432)
- `packages/cylance/data_stream/protect/fields/fields.yml` (line 1432)
- `packages/juniper_netscreen/data_stream/log/fields/fields.yml` (line 1432)
- Matching README field-table entries in each corresponding package docs (`packages/*/docs/README.md`), e.g. `packages/bluecoat/docs/README.md` (line 200).

### 2. Missing punctuation in Amazon Security Lake LDAP DN description family

**Current text:** `...in an X.500 directory service For example, cn=John Doe,ou=People,dc=example,dc=com.`

**Suggested fix:** `...in an X.500 directory service. For example, cn=John Doe,ou=People,dc=example,dc=com.`

**Why:** Two sentences are run together (`service For example`), repeated in many user-facing field descriptions.

**Verified occurrences:**
- `packages/amazon_security_lake/data_stream/application_activity/fields/actor-fields.yml` (line 1690)
- `packages/amazon_security_lake/data_stream/system_activity/fields/actor-fields.yml` (line 1690)
- `packages/amazon_security_lake/data_stream/discovery/fields/actor-fields.yml` (line 1690)
- `packages/amazon_security_lake/data_stream/discovery/fields/user-fields.yml` (line 129)
- `packages/amazon_security_lake/data_stream/event/fields/user-fields.yml` (line 129)
- `packages/amazon_security_lake/data_stream/findings/fields/actor-fields.yml` (line 1690)
- `packages/amazon_security_lake/data_stream/findings/fields/assignee-fields.yml` (line 129)
- `packages/amazon_security_lake/data_stream/network_activity/fields/actor-fields.yml` (line 1690)
- `packages/amazon_security_lake/data_stream/iam/fields/actor-fields.yml` (line 1690)
- `packages/amazon_security_lake/data_stream/iam/fields/user-fields.yml` (line 129)
- Rendered table text in `packages/amazon_security_lake/docs/README.md` (line 1985)

### 3. Cassandra protocol field description has article/spacing errors

**Current text:** `...will be an error code followed by a error message...`

**Suggested fix:** `...will be an error code followed by an error message...`

**Why:** Clear grammar + spacing issue in user-facing field descriptions.

**Verified occurrences:**
- `packages/network_traffic/data_stream/cassandra/fields/protocol.yml` (line 230)
- `packages/network_traffic/data_stream/cassandra/fields/protocol_ecs.yml` (line 230)

### 4. Typo in user-visible Kibana conversion error message

**File:** `dev/import-beats/kibana.go` (line 393)

**Current text:** `Kibana object convertion failed`

**Suggested fix:** `Kibana object conversion failed`

**Why:** Unambiguous typo in an emitted error string.

### 5. Awkward/incorrect Buildkite user-facing messages

**A. File:** `.buildkite/scripts/common.sh` (line 70)

- **Current text:** `The current platform/OS type is unsupported yet`
- **Suggested fix:** `The current platform/OS type is not supported yet`
- **Why:** Clear grammar error.

**B. Files:** `.buildkite/scripts/build_packages.sh` (line 115), `.buildkite/scripts/trigger_publish_packages.sh` (line 17)

- **Current text:** `Please, trigger a new build to avoid issues publishing packages duplicating the artifacts in this build.`
- **Suggested fix:** `Please trigger a new build to avoid publishing duplicate artifacts from this build.`
- **Why:** Awkward, hard-to-parse warning text in user-facing CI output.

## Suggested Actions

- [ ] Replace the `Destination dn` sentence in all listed field definitions and mirrored README tables.
- [ ] Add the missing period before `For example` in all listed Amazon Security Lake field definitions and docs output.
- [ ] Fix `an error` / `a error` in both Cassandra protocol field files.
- [ ] Correct `convertion` -> `conversion` in `dev/import-beats/kibana.go`.
- [ ] Update the two Buildkite message patterns to the suggested clear grammar forms.

---
[What is this?](https://ela.st/github-ai-tools) | [From workflow: Text Auditor](https://github.com/elastic/integrations/actions/runs/27201784500)

Give us feedback! React with 🚀 if perfect, 👍 if helpful, 👎 if not.
> - [x] expires on Jun 16, 2026, 11:12 AM UTC