docs: Add M7 source connectors (10 tasks), M3.5.10 auth integration, remove Kong refs

- M7.1-M7.10: Extensible SourceConnector trait, Obsidian/paperless/git/S3
  connectors, sync framework, CLI, HTTP endpoints, health monitoring, gate
- M3.5.10: Auth integration with Authentik OIDC → Vault token validation
- DESIGN.md: Add source connectors architecture, update auth to
  Authentik/Vault (Kong removed from cluster)
- INDEX.md: 75 tasks, 11 gates
- Fix all Kong references in M3.5.1 task

tasks/M7.10-m7-gate.md

@@ -0,0 +1,92 @@
+# M7.10 — M7 composition gate — source connectors
+
+| Field | Value |
+|---|---|
+| Phase | M7 — Source connectors |
+| Size | M — 1–3 days |
+| Status | ⬜ Not started |
+| Flags | gate |
+| Spec | inlined below |
+| Blocks | — |
+| Depends | M7.1, M7.2, M7.3, M7.6, M7.7, M7.8, M7.9 |
+
+## Goal
+
+Prove the connector framework composes: two different connector kinds sync
+through the same framework, change detection skips unchanged documents, tombstoning
+works, drift reports are accurate, rebuild parity holds, and the gated loop's
+update-rate is untouched.
+
+## What the gate proves
+
+1. **Extensibility works.** Two different connector kinds (at minimum: obsidian +
+   one remote connector) register, sync, and produce queryable Level R content
+   through the same `SyncEngine`. No connector-specific code exists outside the
+   connector itself.
+
+2. **Change detection is efficient.** Re-syncing an unchanged connector produces
+   zero embedding calls. This is the cost guard — without it, every sync is a
+   full re-embed.
+
+3. **Tombstoning is correct.** Removing a document from a source results in
+   tombstone records in the log, removal from the index, and correct behavior
+   on rebuild.
+
+4. **Drift report is read-only.** Running `mem source status` mutates nothing.
+
+5. **Rebuild parity holds for connectors.** `mem rebuild --from-log` with
+   connector-sourced data produces byte-identical results.
+
+6. **Update-rate is untouched.** Adding connector-sourced reference documents
+   does not change the gated loop's update-rate (same property M3.6.6 asserts,
+   now for any connector).
+
+7. **Health monitoring detects failures.** An unreachable connector is reported,
+   not silently ignored.
+
+## Verify
+
+**Integration test** — `tests/it_m7_gate.rs`:
+
+1. `a1_two_kinds_sync` — register an obsidian + vec connector; sync both; assert
+   Level R nodes exist for both sources.
+2. `a2_unchanged_zero_embeds` — re-sync both; assert zero embedding calls.
+3. `a3_change_detected_and_replaced` — modify a doc in one connector; sync;
+   assert old chunks tombstoned, new chunks present.
+4. `a4_removal_tombstoned` — remove a doc; sync; assert tombstone records and
+   doc absent from query results.
+5. `a5_drift_report_is_read_only` — snapshot log + manifest; run status; assert
+   unchanged.
+6. `a6_rebuild_parity` — after full sync, rebuild from log; assert byte-identical
+   state.
+7. `a7_update_rate_untouched` — record update-rate before adding connectors;
+   add connectors + sync; re-run gated loop; assert update-rate unchanged.
+8. `a8_health_failure_reported` — configure unreachable connector; assert
+   health check reports failure.
+9. `a9_no_connector_specific_code_in_sync` — assert `SyncEngine` has no
+   `match kind` or `if kind ==` statements (the trait is the dispatch, not
+   the framework).
+10. `a10_query_returns_connector_content` — sync a connector; query its content;
+    assert results include connector-sourced Level R nodes with correct source_uri.
+
+**Command:** `cargo test --test it_m7_gate`
+
+**False pass:**
+- Testing with only one connector kind. The gate's value is proving two
+  *different* kinds work through the same framework.
+- Testing rebuild parity without connector data in the log. An empty log
+  trivially rebuilds.
+- Asserting update-rate "is still below 30%" instead of "is unchanged". Adding
+  reference docs should not move the number at all.
+
+## Traps
+
+- Running the gate before M7.6 (sync framework) is solid. The gate tests
+  composition; if the sync framework has bugs, every gate assertion fails
+  for the wrong reason.
+- Not testing with a connector that produces multiple chunks per document.
+  Single-chunk documents hide change-detection bugs at the chunk level.
+
+---
+
+Background: [DESIGN.md](../DESIGN.md) — source connectors, composition gates