research + documentation task-prompt templates lack a profile-load section (additive parity gap)

## research + documentation task-prompt templates lack a profile-load section (additive parity gap)

**Task** · Milestone: 3.2.6 · Priority: P3 · Parent epic: #3809

### Gap
The `research` and `documentation` task-prompt templates carry **no profile-load section at
all**, while the software-dev templates do. This is a real cross-mission-type inconsistency —
but **additive** (a missing section to add), not a rename target and not a defect.

### Work
Add the canonical profile-load section (using `/spk-load-profile`, once #3812 lands) to the
research and documentation task-prompt templates, at parity with software-dev.

### Milestone call
Placed in **3.2.6 (P3)** to keep it with the parity cluster, but it is defensible as Product
backlog — it is purely additive and blocks nothing. Left to maintainer discretion.

### Source of truth
- `docs/architecture/profile-load-reliability.md` §3, §4.4 (the missing-section gap is called
out as a **separate additive item**)

> **Freeze note.** Template edits touch doctrine surfaces; may fall under the 3.2.x
> doctrine-surface freeze (`pr:deferred`).

Start with docs/architecture/profile-load-reliability.md §§3 and 4.4, then compare the software-dev task-prompt templates with the research and documentation templates. After /spk-load-profile lands in #3812, add the canonical profile-load section to both missing templates and verify they match the software-dev parity pattern.

Written by the indexing model from the issue text.