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, 39 insertions, 0 deletions

diff --git a/makima/migrations/20260501100000_tmp_directive_and_clear_orphans.sql b/makima/migrations/20260501100000_tmp_directive_and_clear_orphans.sql
new file mode 100644
index 0000000..a587288
--- /dev/null
+++ b/makima/migrations/20260501100000_tmp_directive_and_clear_orphans.sql
@@ -0,0 +1,39 @@
+-- Tmp directive system: every task must belong to a directive going forward.
+--
+-- Background: the unified-surface UI previously surfaced "orphan" tasks
+-- (tasks with directive_id NULL) under a synthetic /tmp/ folder. That
+-- accumulated stale junk over time and made the UI noisy. The new model:
+--
+--   * Add `is_tmp` to directives — at most one per owner, marks the
+--     special "scratchpad" directive that holds otherwise-orphan tasks.
+--   * Delete every existing orphan task. The user explicitly asked for
+--     a clean slate: "ALSO there are TOO MANY old tasks in tmp, we need
+--     to remove all of them as well."
+--   * Going forward, ephemeral / standalone task creation paths attach
+--     to the caller's tmp directive (auto-created on first use by the
+--     repository helper, not by this migration — owners may not exist
+--     yet at migration time, but every owner gets one as soon as a
+--     standalone task is requested).
+--   * A 30-day expiry sweep in the directive reconciler deletes tasks
+--     in tmp directives once they age out.
+
+-- 1. New flag column on directives. Default false; only set true on the
+--    auto-created scratchpad directive.
+ALTER TABLE directives
+    ADD COLUMN is_tmp BOOLEAN NOT NULL DEFAULT false;
+
+-- Partial unique index — at most ONE tmp directive per owner.
+CREATE UNIQUE INDEX idx_directives_owner_tmp_unique
+    ON directives(owner_id)
+    WHERE is_tmp;
+
+-- 2. Clear out every existing orphan task. Per the user's spec these are
+--    discardable scratch work; pre-existing valuable tasks are already
+--    attached to a directive and will not be touched.
+--
+--    Cascades: task_events delete via FK; daemon links go to NULL; nothing
+--    in the contracts/directive_steps tables references orphan tasks (a
+--    contract-backed step always has a directive_id by construction).
+DELETE FROM tasks
+ WHERE directive_id IS NULL
+   AND parent_task_id IS NULL;