docs: create roadmap (4 phases)

Phases:
1. Foundation: Database models and IMAP utilities
2. Account Management: Admin UI for email configuration (ACCT-01 to ACCT-07)
3. Email Ingestion: Sync engine and retention cleanup (SYNC-01 to SYNC-09, RETN-01 to RETN-05)
4. Query Tools: LangChain email analytics (QUERY-01 to QUERY-06)

All v1 requirements mapped to phases.

.planning/ROADMAP.md

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+# Roadmap: SimbaRAG Email Integration
+
+## Overview
+
+Add IMAP email ingestion to SimbaRAG's existing document/finance/meal analytics capabilities. Admin users can configure email accounts, system syncs and embeds emails into ChromaDB on a schedule, automatically purges emails older than 30 days, and provides LangChain tools for inbox analytics through natural conversation.
+
+## Phases
+
+**Phase Numbering:**
+- Integer phases (1, 2, 3): Planned milestone work
+- Decimal phases (2.1, 2.2): Urgent insertions (marked with INSERTED)
+
+Decimal phases appear between their surrounding integers in numeric order.
+
+- [ ] **Phase 1: Foundation** - Database models and IMAP utilities
+- [ ] **Phase 2: Account Management** - Admin UI for configuring email accounts
+- [ ] **Phase 3: Email Ingestion** - Sync engine, embeddings, retention cleanup
+- [ ] **Phase 4: Query Tools** - LangChain tools for email analytics
+
+## Phase Details
+
+### Phase 1: Foundation
+**Goal**: Core infrastructure for email ingestion is in place
+**Depends on**: Nothing (first phase)
+**Requirements**: None (foundational infrastructure)
+**Success Criteria** (what must be TRUE):
+  1. Database tables exist for email accounts, sync status, and email metadata
+  2. IMAP connection utility can authenticate and list folders from test server
+  3. Email body parser extracts text from both plain text and HTML formats
+  4. Encryption utility securely stores and retrieves IMAP credentials
+**Plans**: TBD
+
+Plans:
+- [ ] 01-01: TBD
+
+### Phase 2: Account Management
+**Goal**: Admin users can configure and manage IMAP email accounts
+**Depends on**: Phase 1
+**Requirements**: ACCT-01, ACCT-02, ACCT-03, ACCT-04, ACCT-05, ACCT-06, ACCT-07
+**Success Criteria** (what must be TRUE):
+  1. Admin can add new IMAP account with host, port, username, password, folder selection
+  2. Admin can test IMAP connection and see success/failure before saving
+  3. Admin can view list of configured accounts with masked credentials
+  4. Admin can edit existing account configuration and delete accounts
+  5. Only users in lldap_admin group can access email account endpoints
+**Plans**: TBD
+
+Plans:
+- [ ] 02-01: TBD
+
+### Phase 3: Email Ingestion
+**Goal**: System automatically syncs emails, creates embeddings, and purges old content
+**Depends on**: Phase 2
+**Requirements**: SYNC-01, SYNC-02, SYNC-03, SYNC-04, SYNC-05, SYNC-06, SYNC-07, SYNC-08, SYNC-09, RETN-01, RETN-02, RETN-03, RETN-04, RETN-05
+**Success Criteria** (what must be TRUE):
+  1. System connects to configured IMAP accounts and fetches messages from selected folders
+  2. System parses email metadata (subject, sender, date) and extracts body text from plain/HTML
+  3. System generates embeddings and stores emails in ChromaDB with metadata
+  4. System performs scheduled sync at configurable intervals (default hourly)
+  5. System tracks last sync timestamp and performs incremental sync (only new emails)
+  6. System automatically purges emails older than retention period (default 30 days)
+  7. Admin can view sync logs showing success/failure, counts, and errors
+**Plans**: TBD
+
+Plans:
+- [ ] 03-01: TBD
+
+### Phase 4: Query Tools
+**Goal**: Admin users can query email content through conversational interface
+**Depends on**: Phase 3
+**Requirements**: QUERY-01, QUERY-02, QUERY-03, QUERY-04, QUERY-05, QUERY-06
+**Success Criteria** (what must be TRUE):
+  1. LangChain agent has tool to search emails by content, sender, or date range
+  2. Agent can identify most frequent senders in a timeframe
+  3. Agent can analyze subject lines and identify common topics
+  4. Agent can detect subscription/newsletter patterns (recurring senders, unsubscribe links)
+  5. Agent can answer time-based queries ("emails this week", "emails in January")
+  6. Only admin users can query email content via conversation interface
+**Plans**: TBD
+
+Plans:
+- [ ] 04-01: TBD
+
+## Progress
+
+**Execution Order:**
+Phases execute in numeric order: 1 → 2 → 3 → 4
+
+| Phase | Plans Complete | Status | Completed |
+|-------|----------------|--------|-----------|
+| 1. Foundation | 0/1 | Not started | - |
+| 2. Account Management | 0/1 | Not started | - |
+| 3. Email Ingestion | 0/1 | Not started | - |
+| 4. Query Tools | 0/1 | Not started | - |