feat: harden campaign delivery and editing

src/govoplan_campaign/backend/schemas.py

@@ -58,6 +58,9 @@ class CampaignVersionUpdateRequest(BaseModel):
     source_filename: str | None = None
     source_base_path: str | None = None
     migrate_legacy_mail_settings: bool = False
+    base_revision: int | None = Field(default=None, ge=1)
+    reconciliation_kind: Literal["none", "auto_merge", "manual"] = "none"
+    resolved_conflict_paths: list[str] = Field(default_factory=list, max_length=100)
 
     @field_validator("editor_state")
     @classmethod
@@ -92,6 +95,8 @@ class CampaignVersionResponse(BaseModel):
     id: str
     campaign_id: str
     version_number: int
+    edit_revision: int = 1
+    strong_etag: str = ""
     schema_version: str
     source_filename: str | None = None
     workflow_state: str = "editing"
@@ -440,11 +445,21 @@ class CampaignSendUnattemptedRequest(BaseModel):
 class CampaignSendJobRequest(BaseModel):
     model_config = ConfigDict(extra="forbid")
 
+    kind: Literal["test", "single_send", "single_resend"]
+    idempotency_key: str = Field(min_length=1, max_length=200)
+    reason: str | None = Field(default=None, max_length=2000)
+    context: dict[str, Any] = Field(default_factory=dict)
     include_warnings: bool = True
-    dry_run: bool = False
     use_rate_limit: bool = True
     enqueue_imap_task: bool = False
 
+    @model_validator(mode="after")
+    def require_resend_reason(self):
+        self.reason = (self.reason or "").strip() or None
+        if self.kind == "single_resend" and not self.reason:
+            raise ValueError("single_resend requires a reason")
+        return self
+
 
 class CampaignResolveOutcomeRequest(BaseModel):
     model_config = ConfigDict(extra="forbid")
@@ -626,6 +641,7 @@ class ReportEmailRequest(BaseModel):
     attach_jobs_csv: bool = False
     attach_report_json: bool = False
     dry_run: bool = False
+    idempotency_key: str | None = Field(default=None, min_length=1, max_length=200)
 
     @field_validator("to")
     @classmethod