docs(crm): capture association graph and invoice/mail quirks

Document Medex-learned OO rules (one company, entityId at create, PDF
cache/cleanup, Matrix # truncation) and add invoices pdf/status helpers.

AGENTS.md

@@ -9,7 +9,7 @@ Canonical Go client for OnlyOffice Workspace (Projects + Calendar + CRM) and the
   - `request.go` — `Request`, `Query`, `Time`, `Token`, `MetaResponse`, `Permissions`.
   - `auth.go` — `Authenticate`, `AuthenticateContext`, `InvalidateToken`, `Auth`, token lifecycle.
   - `http.go` — transport + DRY response decoders (`ResponseArray`/`ResponseObject`/`postFormObject`/`putFormObject`/`deleteObject`).
-  - `projects.go`, `tasks.go`, `users.go`, `calendar.go`, `crm.go`, `files.go`, `mails.go` — typed / untyped domain methods. **`files.go`** — CRM opportunity upload plus **project/task Documents** (`GetProjectFiles`, `UploadProjectFile`, `GetTaskFiles`, `AttachFilesToTask`, `UploadTaskFile`, `DetachTaskFile`, `GetFile`, `RenameFile`, `DeleteFiles`, `DownloadFile`). **`mails.go`** — OnlyOffice Workspace Mail addon (`ListMailAccounts`, `ListMailFolders`, `ListMailMessages`, `GetMailMessage`, `RemoveMailMessages`).
+  - `projects.go`, `tasks.go`, `users.go`, `calendar.go`, `crm.go`, `files.go`, `mails.go`, `invoices.go` — typed / untyped domain methods. **`files.go`** — CRM opportunity upload plus **project/task Documents**. **`mails.go`** — OnlyOffice Workspace Mail. **`invoices.go`** — CRM invoices, PDF regen/cleanup, status. Association rules: [`docs/crm-associations.md`](docs/crm-associations.md).
   - Pure stdlib + `google/go-querystring`; no UI, no dotenv.
 - **CLI — `cmd/oo/` as `package main`.** Cobra wrapper that loads `.env` via `godotenv` at startup. **Subject-based command tree** mirroring [`tea`](https://gitea.com/gitea/tea):
   - `main.go` — entry point (docstring lists the command tree).

CHANGELOG.md

@@ -4,6 +4,18 @@ All notable changes to this project are documented here. The format is based on
 [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and this project
 adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Added
+
+* **docs:** CRM association graph and OO quirks (`docs/crm-associations.md`)
+* **crm:** `ForceRegenerateInvoicePDF`, `SetInvoiceStatus`, `PurgeStaleInvoicePDFs`, contact/opportunity file list helpers
+* **oo:** `invoices pdf`, `pdf-cleanup`, `status`; create `--consignee`; draft-invoice force-regens PDF
+
+### Fixed
+
+* Document that invoice→deal must be set at create (`update --opportunity` often HTTP 400)
+
 ## [0.9.0](https://github.com/eSlider/go-onlyoffice/compare/v0.8.3...v0.9.0) (2026-07-26)
 
 

README.md

@@ -623,13 +623,11 @@ oo tasks files detach 208 12345
 | `projects` | `list`, `get`, `milestones`, `create`, `update`, `delete`, **`files`** (`list`, `upload`, `download`, `rename`, `delete`) |
 | `tasks` | `list`, `get`, `create`, `update`, `delete`, `subtask add`, **`files`** (`list`, `upload`, `detach`) |
 | `users` | `list`, `self` (alias: `oo whoami`) |
-| `contacts` | `list`, `get`, `delete`, `info-add` |
+| `contacts` | `list`, `get`, `delete`, `info-add`, `merge`, `dedupe-info` |
-| `persons` | `list` (filtered), `create`, `delete` |
-| `companies` | `list` (filtered), `create`, `delete` |
-| `contacts` | `list`, `get`, `delete`, `info-add`, `dedupe-info` |
 | `persons` | `list`, `create`, `delete`, `dedupe` |
 | `companies` | `list`, `create`, `delete`, `dedupe`, `dedupe-persons` |
 | `opportunities` | `list`, `get`, `create`, `delete`, `stages`, `member-add`, `dedupe`, `dedupe-members`, `fix-titles` |
+| `invoices` | `list`, `get`, `create`, `update`, `pdf`, `pdf-cleanup`, `status`, `delete`, `items …` |
 | `crm` | `cleanup` |
 | `mails` | `accounts`, `folders`, `list`, `get`, `draft`, `attach`, `draft-invoice`, `delete` |
 | `cases` | `list`, `create`, `delete`, `member-add` |
@@ -718,6 +716,32 @@ oo opportunities dedupe-members
 oo opportunities fix-titles
 ```
 
+Merge two known company ids (keeps `INTO`):
+
+```bash
+oo contacts merge FROM_ID INTO_ID
+```
+
+Company ↔ person ↔ deal ↔ project ↔ invoice ↔ mail rules and OO quirks:
+[docs/crm-associations.md](docs/crm-associations.md).
+
+### Invoices (`oo invoices`)
+
+**Problem:** Bill a client deal as Draft, regenerate PDF, prune duplicate PDF
+attachments, prepare OnlyOffice Mail — without inventing a second bill-to company.
+
+```bash
+# Always pass --opportunity at create (update --opportunity often HTTP 400)
+oo invoices create --number INV-2026-01 --contact COMPANY_ID --item ITEM_ID \
+  --price 300 --opportunity DEAL_ID --language de-DE \
+  --line-description "…" --terms $'…' --description $'…' --po "Deal #DEAL_ID"
+
+oo invoices pdf 41 --force
+oo invoices pdf-cleanup INVOICE_ID
+oo invoices status INVOICE_ID --status draft
+oo mails draft-invoice --invoice INVOICE_ID --to info@client.de
+```
+
 **Deal grouping flag** — when the same role at the same company created
 separate deals (`Engineer @ Acme` vs `Engineer`):
 
@@ -829,10 +853,13 @@ oo mails draft --to client@example.com --subject "Rechnung INV-2026-01" \
 # Attach an OnlyOffice Files document (e.g. invoice PDF file id) to a draft
 oo mails attach 7301 --file-id 12345
 
-# Regenerate invoice PDF + draft + attach (does not send)
+# Regenerate invoice PDF (force) + draft + attach (does not send)
 oo mails draft-invoice --invoice 16 --to info@example.com
 ```
 
+Matrix / chat URLs in signatures: use plain text
+`chat: https://matrix.to/#/@user:server` — HTML `<a href="…#…">` truncates at `#`.
+
 **Table output** splits the `from` header into `fromName` and `fromAddress`
 (e.g. `Bitfinex` + `no-reply@bitfinex.com`). **JSON output** returns the raw
 API payload.

cmd/oo/invoices.go

@@ -21,6 +21,9 @@ func init() {
 	invoicesCmd.AddCommand(invoiceGetCmd())
 	invoicesCmd.AddCommand(invoiceCreateCmd())
 	invoicesCmd.AddCommand(invoiceUpdateCmd())
+	invoicesCmd.AddCommand(invoicePDFCmd())
+	invoicesCmd.AddCommand(invoicePDFCleanupCmd())
+	invoicesCmd.AddCommand(invoiceStatusCmd())
 	invoicesCmd.AddCommand(invoiceDeleteCmd())
 	invoicesCmd.AddCommand(invoiceItemsCmd())
 }
@@ -78,7 +81,7 @@ func invoiceGetCmd() *cobra.Command {
 func invoiceCreateCmd() *cobra.Command {
 	var (
 		number, issueDate, dueDate, language, currency, terms, description, po string
-		contactID, itemID, opportunityID                                       int64
+		contactID, consigneeID, itemID, opportunityID                          int64
 		price, qty                                                             float64
 		lineDesc                                                               string
 	)
@@ -87,8 +90,11 @@ func invoiceCreateCmd() *cobra.Command {
 		Short: "Create a draft invoice with one line",
 		Long: `Create a CRM invoice (Draft) with a single line.
 
+Always pass --opportunity when a deal exists (entity link at create). Updating
+--opportunity later often fails with HTTP 400 — see docs/crm-associations.md.
+
 Example:
-  oo invoices create --number INV-2026-01 --contact 123 --item 10 \
+  oo invoices create --number INV-2026-01 --contact CONTACT_ID --item 12 \
     --price 300 --opportunity OPPORTUNITY_ID --line-description "Service package" \
     --terms "…payment terms…"
 `,
@@ -118,6 +124,7 @@ Example:
 				IssueDate:           issueDate,
 				DueDate:             dueDate,
 				ContactID:           contactID,
+				ConsigneeID:         consigneeID,
 				EntityID:            opportunityID,
 				EntityType:          0, // Opportunity
 				Language:            language,
@@ -142,8 +149,9 @@ Example:
 		},
 	}
 	cmd.Flags().StringVar(&number, "number", "", "invoice number (e.g. INV-2026-01)")
-	cmd.Flags().Int64Var(&contactID, "contact", 0, "bill-to contact id (company preferred)")
+	cmd.Flags().Int64Var(&contactID, "contact", 0, "bill-to company contact id (canonical company, not a PDF-only clone)")
-	cmd.Flags().Int64Var(&opportunityID, "opportunity", 0, "link to CRM opportunity/deal id")
+	cmd.Flags().Int64Var(&consigneeID, "consignee", 0, "optional Empfänger person/contact id")
+	cmd.Flags().Int64Var(&opportunityID, "opportunity", 0, "link to CRM opportunity/deal id (set at create)")
 	cmd.Flags().Int64Var(&itemID, "item", 0, "catalog invoice item id")
 	cmd.Flags().Float64Var(&price, "price", 0, "line price")
 	cmd.Flags().Float64Var(&qty, "qty", 1, "line quantity")
@@ -163,8 +171,13 @@ func invoiceUpdateCmd() *cobra.Command {
 	var description, po, terms string
 	cmd := &cobra.Command{
 		Use:   "update INVOICE_ID",
-		Short: "Update invoice (opportunity link, notes, PO, terms)",
+		Short: "Update invoice (notes, PO, terms; opportunity link unreliable)",
-		Args:  cobra.ExactArgs(1),
+		Long: `Update Draft invoice fields.
+
+--opportunity often returns HTTP 400 on existing invoices. Prefer
+oo invoices create … --opportunity, or delete+recreate. See docs/crm-associations.md.
+`,
+		Args: cobra.ExactArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			if opportunityID == 0 && !cmd.Flags().Changed("description") && !cmd.Flags().Changed("po") && !cmd.Flags().Changed("terms") {
 				return fmt.Errorf("set --opportunity and/or --description and/or --po and/or --terms")
@@ -190,13 +203,129 @@ func invoiceUpdateCmd() *cobra.Command {
 			return nil
 		},
 	}
-	cmd.Flags().Int64Var(&opportunityID, "opportunity", 0, "CRM opportunity/deal id to link")
+	cmd.Flags().Int64Var(&opportunityID, "opportunity", 0, "CRM opportunity/deal id (may 400 — prefer create)")
 	cmd.Flags().StringVar(&description, "description", "", "invoice notes (Notizen); use \\n for line breaks")
 	cmd.Flags().StringVar(&po, "po", "", "purchase order number")
 	cmd.Flags().StringVar(&terms, "terms", "", "payment terms / footer (Bedingungen)")
 	return cmd
 }
 
+func invoicePDFCmd() *cobra.Command {
+	var force bool
+	cmd := &cobra.Command{
+		Use:   "pdf INVOICE_ID",
+		Short: "Return / regenerate invoice PDF file metadata",
+		Long: `GET /api/2.0/crm/invoice/{id}/pdf.
+
+With --force, touches the Draft to clear cached fileID first (layout changes).
+`,
+		Args: cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			c, err := newOO(cmd)
+			if err != nil {
+				return err
+			}
+			var out map[string]any
+			if force {
+				out, err = c.ForceRegenerateInvoicePDF(cmd.Context(), args[0])
+			} else {
+				out, err = c.InvoicePDFFile(cmd.Context(), args[0])
+			}
+			if err != nil {
+				return err
+			}
+			printObject(out)
+			return nil
+		},
+	}
+	cmd.Flags().BoolVar(&force, "force", false, "clear PDF cache then regenerate")
+	return cmd
+}
+
+func invoicePDFCleanupCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "pdf-cleanup INVOICE_ID",
+		Short: "Delete older P-*.pdf copies on company/deal; keep invoice.fileID",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			c, err := newOO(cmd)
+			if err != nil {
+				return err
+			}
+			deleted, err := c.PurgeStaleInvoicePDFs(cmd.Context(), args[0])
+			if err != nil {
+				return err
+			}
+			if outputFormat == "json" {
+				printObject(map[string]any{"deleted": deleted})
+				return nil
+			}
+			fmt.Printf("deleted %d stale PDF file(s): %v\n", len(deleted), deleted)
+			return nil
+		},
+	}
+}
+
+func invoiceStatusCmd() *cobra.Command {
+	var status string
+	cmd := &cobra.Command{
+		Use:   "status INVOICE_ID [INVOICE_ID...]",
+		Short: "Set invoice status (draft|billed|rejected|paid)",
+		Long: `PUT /api/2.0/crm/invoice/status/{id}.
+
+Billed invoices are not content-editable. Billed→Draft often does not work —
+recreate as Draft instead (docs/crm-associations.md).
+`,
+		Args: cobra.MinimumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			statusID, err := parseInvoiceStatus(status)
+			if err != nil {
+				return err
+			}
+			ids := make([]int64, 0, len(args))
+			for _, a := range args {
+				var id int64
+				if _, err := fmt.Sscan(a, &id); err != nil || id <= 0 {
+					return fmt.Errorf("invalid invoice id %q", a)
+				}
+				ids = append(ids, id)
+			}
+			c, err := newOO(cmd)
+			if err != nil {
+				return err
+			}
+			out, err := c.SetInvoiceStatus(cmd.Context(), statusID, ids...)
+			if err != nil {
+				return err
+			}
+			printObject(out)
+			return nil
+		},
+	}
+	cmd.Flags().StringVar(&status, "status", "draft", "draft|billed|rejected|paid or numeric id")
+	return cmd
+}
+
+func parseInvoiceStatus(s string) (int, error) {
+	s = strings.TrimSpace(strings.ToLower(s))
+	switch s {
+	case "", "draft", "1":
+		return onlyoffice.InvoiceStatusDraft, nil
+	case "billed", "2":
+		return onlyoffice.InvoiceStatusBilled, nil
+	case "rejected", "3":
+		return onlyoffice.InvoiceStatusRejected, nil
+	case "paid", "4":
+		return onlyoffice.InvoiceStatusPaid, nil
+	default:
+		var n int
+		if _, err := fmt.Sscan(s, &n); err != nil || n <= 0 {
+			return 0, fmt.Errorf("unknown status %q (draft|billed|rejected|paid)", s)
+		}
+		return n, nil
+	}
+}
+
 func invoiceDeleteCmd() *cobra.Command {
 	return &cobra.Command{
 		Use:   "delete INVOICE_ID [INVOICE_ID...]",

cmd/oo/mails.go

@@ -229,7 +229,7 @@ Does not send. Open /addons/mail/#drafts to review.
 			if err != nil {
 				return err
 			}
-			pdf, err := c.InvoicePDFFile(cmd.Context(), strconv.Itoa(invoiceID))
+			pdf, err := c.ForceRegenerateInvoicePDF(cmd.Context(), strconv.Itoa(invoiceID))
 			if err != nil {
 				return err
 			}

cmd/oo/main.go

@@ -6,18 +6,20 @@
 //	oo projects      list | get | milestones | create | update | delete | files (list|upload|download|rename|delete)
 //	oo tasks         list | get | create | update | delete | subtask add | files (list|upload|detach)
 //	oo users         list | self            (alias: oo whoami)
-//	oo contacts      list | get | delete | info-add | dedupe-info
+//	oo contacts      list | get | delete | info-add | merge | dedupe-info
 //	oo persons       list | create | delete | dedupe
 //	oo companies     list | create | delete | dedupe | dedupe-persons
 //	oo opportunities list | get | create | delete | stages | member-add | dedupe | dedupe-members | fix-titles
 //	oo cases         list | create | delete | member-add
 //	oo crm-tasks     list | create | delete | categories
 //	oo crm           cleanup
-//	oo mails         accounts | folders | list | get | delete
+//	oo mails         accounts | folders | list | get | draft | attach | draft-invoice | delete
-//	oo invoices      list | get | create | delete | items (list|create|delete)
+//	oo invoices      list | get | create | update | pdf | pdf-cleanup | status | delete | items …
 //	oo applications  sync
 //	oo catalog       scan-contacts | scan-projects | scan-thunderbird | merge | match | apply
 //
+// CRM association rules: docs/crm-associations.md
+//
 // Every list supports `--output/-o json|table` (table is the default).
 //
 // Build & install:

docs/crm-associations.md

@@ -0,0 +1,120 @@
+# CRM associations (company ↔ person ↔ deal ↔ project ↔ invoice ↔ mail)
+
+Operational rules learned from real billing work (AcmeClient INV-2026-01, AcmeProject INV-2026-01).
+Tooling: `oo` CLI + this library. Business SSOT remains OnlyOffice (`ASR-0002`).
+
+## Canonical graph
+
+One **legal company** owns the relationship. Do not invent a second “bill-to”
+company just for PDF layout.
+
+```text
+Company (#CONTACT_ID)
+├── Person (GF / buyer contact)     oo persons create --company-id
+├── Opportunity / Deal              oo opportunities … ; member-add company + person
+├── Project (hub)                   oo projects … ; contacts add company + person
+│     └── Epic + subtasks
+└── Invoice (Draft → …)             oo invoices create --contact COMPANY --opportunity DEAL
+      └── PDF file                  oo invoices pdf ID
+            └── Mail draft          oo mails draft-invoice --invoice ID --to …
+```
+
+| Layer | CLI | Must link |
+|-------|-----|-----------|
+| Company | `oo companies create` | website, email, phone, **one** Billing address |
+| Person | `oo persons create --company-id` | job title; never encode employer in `lastName` |
+| Deal | `oo opportunities create` + `member-add` | company **and** person as members |
+| Project | `oo projects create` + `contacts add` | same company + person |
+| Invoice | `oo invoices create --contact COMPANY --opportunity DEAL` | `entityId` at **create** |
+| Mail | `oo mails draft-invoice` | attach current PDF; **do not send** until confirmed |
+
+UI checks (same company card):
+
+- `#contacts` → person  
+- `#deals` → opportunity  
+- `#projects` → hub project  
+- `#invoices` on the **deal** → invoice (needs `entity`)  
+- `#files` → preferably **one** current `P-….pdf`
+
+## Hard rules
+
+1. **One company per legal entity.** Duplicate “bill-to” contacts empty Deals /
+   Projects / Contacts tabs and break merge. Prefer
+   `oo contacts merge FROM INTO` (keeps `INTO`) or `oo companies dedupe`.
+2. **Link invoice → deal at create.**  
+   `POST /crm/invoice` with `entityId` + `entityType: 0` (Opportunity).  
+   `oo invoices update … --opportunity` often returns **400**
+   (“Value does not fall within the expected range”). If the link is missing,
+   delete the Draft and recreate with `--opportunity`.
+3. **Bill To = company id**, not a throwaway contact. Person stays under the
+   company (`companyId`). Optional `consigneeId` for Empfänger when the portal
+   template prints it.
+4. **Stay Draft until mail is ready.** Billed (`status id=2`) is **not editable**
+   via content PUT. Going Billed → Draft via `…/crm/invoice/status/1` usually
+   **does not work** — delete + recreate Draft instead.
+5. **Do not regenerate PDF in a loop** without cleanup. Each
+   `GET …/crm/invoice/{id}/pdf` attaches a new file to the company (and often
+   the deal). Keep `invoice.fileID`; delete older `P-*.pdf` with
+   `oo invoices pdf-cleanup ID` / Documents `fileops/delete`.
+
+## Invoice PDF quirks
+
+| Symptom | Workaround |
+|---------|------------|
+| Cached / stale PDF | Touch invoice (Draft PUT that clears `fileID`), then `GET …/pdf` — `oo invoices pdf ID --force` |
+| Billing address missing on **new** PDFs | Temporary multiline `companyName` (`Line1\nLine2\n…`) on the **canonical** company → force PDF → restore clean name. Cached `fileID` keeps the multiline Bill To. |
+| Separate bill-to company for newlines | **Forbidden** — merge back to the real company |
+| Invoice **number** won’t change on PUT | Delete Draft and recreate with the desired number |
+| Notizen / Bedingungen spacing | Leading `\n` and blank lines only — no HTML (tags print literally) |
+| Issuer NIE / street lines | Organisation profile address (`street` with `\n`), not only terms |
+
+Status ids commonly used on this portal: `1` Draft, `2` Billed, `3` Rejected, `4` Paid.
+
+## Mail quirks
+
+| Symptom | Workaround |
+|---------|------------|
+| Signature / body cuts Matrix URL at `#` | Plain text `chat: https://matrix.to/#/@user:server` — avoid `<a href="…#…">` (or encode `#` as `%23` in href) |
+| German letter spacing | Blank `<p>&nbsp;</p>` between blocks (`MailHTMLWithBlankParagraphs`) |
+| Send | Never auto-send; draft only until the human confirms |
+
+Prefer OnlyOffice Mail (`/addons/mail/#drafts`) over Gmail MCP for invoice delivery.
+
+## Project / task quirks
+
+- Hub title: `CC | Company` (e.g. `DE | AcmeClient Ambulanter Pflegedienst GmbH`).
+- Streams = epics/tasks under the hub, not a third title segment (unless the
+  project itself is a named delivery stream).
+- Closing a **subtask**:  
+  `PUT /api/2.0/project/task/{epicId}/{subtaskId}/status` with `status=2`.  
+  `oo tasks update SUBTASK -s closed` returns **404** for subtasks.
+- After deleting a CRM contact, `GET /project/contact/{deletedId}` may still
+  return projects (ghost). Official project contact list should only show live
+  ids; unlink may 400 if the contact is gone.
+
+## Merge / cleanup cheat sheet
+
+```bash
+# Keep the human-created company (INTO), drop the duplicate (FROM)
+oo contacts merge 1334 1328
+
+# Or by normalized name (careful — whole CRM)
+oo companies dedupe
+
+# Invoice ↔ deal must exist at create
+oo invoices create --number P-YYYY-NN --contact CONTACT_ID --item N \
+  --price 300 --opportunity OPPORTUNITY_ID --language de-DE …
+
+# Fresh PDF + prune older P-*.pdf on company/deal
+oo invoices pdf 41 --force
+oo invoices pdf-cleanup INVOICE_ID
+
+# Mail draft (no send)
+oo mails draft-invoice --invoice INVOICE_ID --to info@client.de
+```
+
+## Related
+
+- README § invoices / mail / CRM cleanup  
+- Skill `oo-clients-projects` (Cursor)  
+- inventar ASR-0014 / `ops/oo-clients-contacts-sync.md`

invoices.go

@@ -129,6 +129,9 @@ type UpdateInvoiceParams struct {
 }
 
 // UpdateInvoice PUTs a full invoice body (OnlyOffice requires complete payload).
+//
+// Linking an opportunity via EntityID on an existing invoice often returns HTTP 400
+// on this portal — prefer CreateInvoice with EntityID set. See docs/crm-associations.md.
 func (c *Client) UpdateInvoice(ctx context.Context, id string, p UpdateInvoiceParams) (map[string]any, error) {
 	inv, err := c.GetInvoice(ctx, id)
 	if err != nil {
@@ -236,6 +239,161 @@ func (c *Client) DeleteInvoice(ctx context.Context, id string) (map[string]any,
 	return c.deleteObject(ctx, fmt.Sprintf("/api/2.0/crm/invoice/%s.json", url.PathEscape(id)))
 }
 
+// Invoice status ids used by OnlyOffice CRM on produktor.io.
+const (
+	InvoiceStatusDraft    = 1
+	InvoiceStatusBilled   = 2
+	InvoiceStatusRejected = 3
+	InvoiceStatusPaid     = 4
+)
+
+// SetInvoiceStatus sets CRM invoice status for one or more invoice ids
+// (PUT /api/2.0/crm/invoice/status/{statusId} with invoiceids).
+// Note: Billed→Draft often does not stick; recreate Draft instead (see docs/crm-associations.md).
+func (c *Client) SetInvoiceStatus(ctx context.Context, statusID int, invoiceIDs ...int64) (map[string]any, error) {
+	if statusID <= 0 {
+		return nil, fmt.Errorf("status id is required")
+	}
+	if len(invoiceIDs) == 0 {
+		return nil, fmt.Errorf("at least one invoice id is required")
+	}
+	ids := make([]string, 0, len(invoiceIDs))
+	for _, id := range invoiceIDs {
+		ids = append(ids, strconv.FormatInt(id, 10))
+	}
+	fields := url.Values{}
+	fields.Set("invoiceids", strings.Join(ids, ","))
+	return c.putFormObject(ctx, fmt.Sprintf("/api/2.0/crm/invoice/status/%d", statusID), fields)
+}
+
+// InvoicePDFFile returns invoice PDF file metadata (id, title, viewUrl).
+// Without force, OnlyOffice may return a cached fileID with stale layout.
+func (c *Client) InvoicePDFFile(ctx context.Context, invoiceID string) (map[string]any, error) {
+	id := strings.TrimSpace(invoiceID)
+	if id == "" {
+		return nil, fmt.Errorf("InvoicePDFFile: invoice id is required")
+	}
+	return c.ResponseObject(ctx, fmt.Sprintf("/api/2.0/crm/invoice/%s/pdf", url.PathEscape(id)))
+}
+
+// ForceRegenerateInvoicePDF clears the cached PDF (Draft touch) then requests a new file.
+// No-op touch when the invoice is not editable (e.g. Billed) — falls back to GET /pdf.
+func (c *Client) ForceRegenerateInvoicePDF(ctx context.Context, invoiceID string) (map[string]any, error) {
+	id := strings.TrimSpace(invoiceID)
+	if id == "" {
+		return nil, fmt.Errorf("ForceRegenerateInvoicePDF: invoice id is required")
+	}
+	inv, err := c.GetInvoice(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	canEdit := true
+	if v, ok := inv["canEdit"].(bool); ok {
+		canEdit = v
+	}
+	if canEdit {
+		desc := stringField(inv, "description")
+		// Append/remove a trailing space so PUT clears fileID without visible change.
+		touch := desc + " "
+		if strings.HasSuffix(desc, " ") {
+			touch = strings.TrimSuffix(desc, " ")
+		}
+		if _, err := c.UpdateInvoice(ctx, id, UpdateInvoiceParams{
+			Description:    touch,
+			DescriptionSet: true,
+		}); err != nil {
+			return nil, fmt.Errorf("ForceRegenerateInvoicePDF: clear cache: %w", err)
+		}
+	}
+	return c.InvoicePDFFile(ctx, id)
+}
+
+// ListCRMContactFiles lists Documents attached on a CRM contact card (#files).
+func (c *Client) ListCRMContactFiles(ctx context.Context, contactID string) ([]map[string]any, error) {
+	return c.ResponseArray(ctx, fmt.Sprintf("/api/2.0/crm/contact/%s/files.json", url.PathEscape(contactID)))
+}
+
+// ListOpportunityFiles lists Documents attached on a CRM opportunity.
+func (c *Client) ListOpportunityFiles(ctx context.Context, opportunityID string) ([]map[string]any, error) {
+	return c.ResponseArray(ctx, fmt.Sprintf("/api/2.0/crm/opportunity/%s/files.json", url.PathEscape(opportunityID)))
+}
+
+// PurgeStaleInvoicePDFs deletes older P-*.pdf copies on the invoice contact (and linked
+// opportunity) while keeping the invoice's current fileID. Returns deleted file ids.
+func (c *Client) PurgeStaleInvoicePDFs(ctx context.Context, invoiceID string) ([]int, error) {
+	inv, err := c.GetInvoice(ctx, invoiceID)
+	if err != nil {
+		return nil, err
+	}
+	keep := flexInt(inv["fileID"])
+	number := strings.TrimSpace(stringField(inv, "number"))
+	base := number
+	for strings.HasSuffix(base, "b") || strings.HasSuffix(base, "B") {
+		base = base[:len(base)-1]
+	}
+	if base == "" {
+		base = "P-"
+	}
+
+	seen := map[int]struct{}{}
+	var candidates []int
+	addFiles := func(files []map[string]any) {
+		for _, f := range files {
+			title := stringField(f, "title")
+			id := int(flexInt(f["id"]))
+			if id == 0 || id == int(keep) {
+				continue
+			}
+			if !strings.HasPrefix(title, "P-") {
+				continue
+			}
+			if !strings.HasPrefix(title, base) {
+				continue
+			}
+			if _, ok := seen[id]; ok {
+				continue
+			}
+			seen[id] = struct{}{}
+			candidates = append(candidates, id)
+		}
+	}
+
+	if m, ok := inv["contact"].(map[string]any); ok {
+		cid := strconv.FormatInt(flexInt(m["id"]), 10)
+		if cid != "0" {
+			files, err := c.ListCRMContactFiles(ctx, cid)
+			if err != nil {
+				return nil, err
+			}
+			addFiles(files)
+		}
+	}
+	if ent, ok := inv["entity"].(map[string]any); ok && ent != nil {
+		if strings.EqualFold(fmt.Sprint(ent["entityType"]), "opportunity") || flexInt(ent["entityType"]) == 0 {
+			oid := strconv.FormatInt(flexInt(ent["entityId"]), 10)
+			if oid != "0" {
+				files, err := c.ListOpportunityFiles(ctx, oid)
+				if err != nil {
+					return nil, err
+				}
+				addFiles(files)
+			}
+		}
+	}
+
+	if len(candidates) == 0 {
+		return nil, nil
+	}
+	if err := c.DeleteFiles(ctx, candidates); err != nil {
+		return nil, err
+	}
+	// CRM may still list deleted files briefly; also try CRM unlink.
+	for _, fid := range candidates {
+		_, _ = c.deleteObject(ctx, fmt.Sprintf("/api/2.0/crm/files/%d.json", fid))
+	}
+	return candidates, nil
+}
+
 // ListInvoiceItems returns catalog invoice items.
 func (c *Client) ListInvoiceItems(ctx context.Context, count, startIndex int) ([]map[string]any, int, error) {
 	q := url.Values{}

mails.go

@@ -198,15 +198,6 @@ func (c *Client) AttachMailDocument(ctx context.Context, messageID string, fileI
 	return c.postFormObject(ctx, fmt.Sprintf("/api/2.0/mail/messages/%s/document", url.PathEscape(id)), fields)
 }
 
-// InvoicePDFFile regenerates/returns the invoice PDF file metadata (id, title, viewUrl).
-func (c *Client) InvoicePDFFile(ctx context.Context, invoiceID string) (map[string]any, error) {
-	id := strings.TrimSpace(invoiceID)
-	if id == "" {
-		return nil, fmt.Errorf("InvoicePDFFile: invoice id is required")
-	}
-	return c.ResponseObject(ctx, fmt.Sprintf("/api/2.0/crm/invoice/%s/pdf", url.PathEscape(id)))
-}
-
 // PlainTextToMailHTML turns plain text into simple HTML paragraphs for drafts.
 // If s already looks like HTML, it is returned unchanged.
 func PlainTextToMailHTML(s string) string {