chore(cleanup): Phase 5 contracts removal + tmp directive + 30-day expiry + scroll fix (#118)

Sweeping cleanup across the surface and the wire. Net: -14k LOC of legacy
contracts code, plus the tmp/scroll/UX fixes the user asked for.

## Sidebar/editor independent scroll
Replace `height: calc(100vh - 80px)` (which assumed an 80px masthead and
quietly clipped or pushed the whole page below the fold when the masthead
was taller) with `h-screen + overflow-hidden` on the page root and proper
`flex-1 min-h-0` sizing on `<main>`. Sidebar and editor pane now manage
their own scroll independently; the page itself never scrolls.

Same fix in /tmp/:taskId.

## tmp directive — real backing for orphans/ephemerals

New migration `20260501100000_tmp_directive_and_clear_orphans.sql`:
  * Adds `directives.is_tmp` BOOLEAN NOT NULL DEFAULT false.
  * Partial unique index `(owner_id) WHERE is_tmp` — at most ONE tmp
    directive per owner.
  * Hard-deletes every existing orphan task (`directive_id IS NULL`).
    Per the user spec: "ALSO there are TOO MANY old tasks in tmp, we
    need to remove all of them as well."

New repository helpers:
  * `get_or_create_tmp_directive(pool, owner_id) -> Directive`
    INSERT ON CONFLICT DO NOTHING + fallback SELECT, race-safe.
  * `list_all_tmp_directives` — drives the expiry sweep.
  * `delete_expired_tmp_tasks(tmp_directive_id) -> u64`.
  * `list_tmp_tasks_for_owner` (replaces `list_orphan_tasks_for_owner`).

`mesh::create_task`: every top-level task must have a directive. If a
caller doesn't supply `directive_id` and isn't a subtask, attach to the
caller's tmp directive (auto-creating it on first use).

`list_directives_for_owner` filters out `is_tmp=true` so the scratchpad
directive doesn't pollute the contract list — surfaced via the sidebar's
`tmp/` folder instead.

## 30-day expiry on tmp tasks

New `phase_tmp_expiry` in the directive reconciler. Throttled to once per
hour: enumerates every tmp directive, calls `delete_expired_tmp_tasks`,
logs the count. The actual delete is `WHERE created_at < NOW() - INTERVAL
'30 days'` and is fast on the existing index. Subtasks die via FK cascade.

## Phase 5 — contracts removed

### Frontend
Deleted entire `/contracts` surface:
  * routes: `contracts.tsx`, `contract-file.tsx`
  * components/contracts: ContractList, ContractDetail, ContractCliInput,
    ContractContextMenu, CommandModePanel, PhaseBadge, PhaseHint,
    PhaseDeliverablesPanel, PhaseProgressBar, QuickActionButtons,
    RepositoryPanel, TaskDerivationPreview
  * (Kept `PhaseConfirmationModal` — used outside the contracts surface
    by `TaskOutput` and `PhaseConfirmationNotification`.)
  * Routes deregistered from `main.tsx`; nav entry removed from
    `NavStrip`.

### Backend handlers
Deleted: `contracts.rs` (2.4k LOC), `contract_chat.rs` (3.2k LOC),
`contract_daemon.rs` (~940 LOC), `contract_discuss.rs` (~590 LOC),
`transcript_analysis.rs` (~690 LOC). All `/api/v1/contracts/*` routes
deregistered. OpenAPI entries dropped. Module declarations removed from
`server/handlers/mod.rs`.

### CLI
Removed `makima contract` and `makima supervisor` subcommands. Deleted
`daemon/cli/contract.rs` and `daemon/cli/supervisor.rs`. Bin dispatch
trimmed (~377 LOC).

### Orchestrator
Removed the contract-spawn path from `phase_execution`
(`spawn_step_contract` and its caller). `directive_steps.contract_type`
now logs a warning and falls through to standalone-task spawn. Column
itself stays — old data still reads, just no longer triggers a
contract+supervisor spawn.

### TUI
`Action::PerformCreateContract` is now a no-op that surfaces a status
message: "Contracts have been removed. Use directives instead." The TUI
form is dead code pending a wider refresh.

## Out of scope (deliberately left)

* Contracts DB tables (`contracts`, `contract_repositories`,
  `contract_chat_history`, `contract_events`, `contract_templates`) are
  retained for historical data + because some peripheral code still
  joins to them in TaskSummary queries.
* `mesh_supervisor` handlers are retained — they aren't only used by
  contracts (some mesh-level supervisor behaviour persists), and the
  cross-cutting cleanup is bigger than this PR.
* `directive_steps.contract_type` column itself isn't dropped; just no
  longer functional.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

1 files changed, 32 insertions, 2 deletions

diff --git a/makima/src/server/handlers/mesh.rs b/makima/src/server/handlers/mesh.rs
index ac5652a..63b1827 100644
--- a/makima/src/server/handlers/mesh.rs
+++ b/makima/src/server/handlers/mesh.rs
@@ -122,7 +122,11 @@ pub async fn list_tasks(
     };
 
     let result = if query.orphan {
-        repository::list_orphan_tasks_for_owner(pool, auth.owner_id).await
+        // Backed by the per-owner tmp directive going forward — see
+        // `list_tmp_tasks_for_owner` for the semantics. The query parameter
+        // name (`?orphan=true`) is preserved for backwards compatibility
+        // with existing frontend callers.
+        repository::list_tmp_tasks_for_owner(pool, auth.owner_id).await
     } else {
         repository::list_tasks_for_owner(pool, auth.owner_id).await
     };
@@ -228,7 +232,7 @@ pub async fn get_task(
 pub async fn create_task(
     State(state): State<SharedState>,
     Authenticated(auth): Authenticated,
-    Json(req): Json<CreateTaskRequest>,
+    Json(mut req): Json<CreateTaskRequest>,
 ) -> impl IntoResponse {
     let Some(ref pool) = state.db_pool else {
         return (
@@ -238,6 +242,32 @@ pub async fn create_task(
             .into_response();
     };
 
+    // Every top-level task must live under SOME directive going forward —
+    // the unified directive surface is the only way users see tasks. If a
+    // caller doesn't supply directive_id, attach to the owner's tmp
+    // (scratchpad) directive, auto-creating it if needed. Subtasks
+    // (parent_task_id set) inherit their parent's directive linkage and
+    // are fine without an explicit directive_id.
+    if req.directive_id.is_none() && req.parent_task_id.is_none() {
+        match repository::get_or_create_tmp_directive(pool, auth.owner_id).await {
+            Ok(tmp) => {
+                req.directive_id = Some(tmp.id);
+            }
+            Err(e) => {
+                tracing::error!(
+                    owner_id = %auth.owner_id,
+                    error = %e,
+                    "Failed to provision tmp directive for orphan task"
+                );
+                return (
+                    StatusCode::INTERNAL_SERVER_ERROR,
+                    Json(ApiError::new("TMP_PROVISION_FAILED", &e.to_string())),
+                )
+                    .into_response();
+            }
+        }
+    }
+
     match repository::create_task_for_owner(pool, auth.owner_id, req).await {
         Ok(task) => {
             // Record history event for task creation