fix(archive): derive <company>_<role> as a single path component (#329)

Extends the canonical Subfolder-naming rule by citation to all six archive derivation sites (apply, gmail-sync, interview, notion-sync, outcome, assistant SKILL.md), adds a fail-closed guard for an empty derived name, and pins every site with mutation-verified tests. framework_version 1.3.3 -> 1.3.4.

jakob1379 independently specified the same fix in his fork's issue #22 before this PR's rework.

Co-authored-by: ayobamiseun <66267222+ayobamiseun@users.noreply.github.com>

.claude/commands/interview.md

@@ -21,7 +21,7 @@ v1 preps for a **specific application**. Generic no-target practice is out of sc
 
 ## Step 1: Load the Application Context
 
-1. **The archive** (started by `/apply`, maintained by `/outcome`): `documents/applications/<company>_<role>/`
+1. **The archive** (started by `/apply`, maintained by `/outcome`): derive `<company>_<role>` by the **Subfolder naming** rule in `documents/README.md`, then use `documents/applications/<company>_<role>/`.
    - `job_posting.md` - the exact posting the user applied to
    - `cv_draft.tex` and `cover_letter.tex` - what was actually submitted. **These are what the interviewer read**; every talking point must be consistent with their claims.
    - `outcome.md` - the stage reached so far and any recorded feedback from earlier stages. Feedback from stage N is the highest-value input for stage N+1 prep.
@@ -76,7 +76,7 @@ Pick 4-6 from `07`'s categories, customized to the research and the stage: role
 ### 6. Logistics
 The phone/video tips from `07` when the format calls for them, plus date and interviewer names as a header.
 
-Save the pack to `documents/applications/<company>_<role>/interview_prep_<stage>.md` (create the folder if this application predates `/outcome`). The folder is gitignored, so the pack stays personal; one file per stage, so earlier packs remain as history. Present the pack in chat as well - the file is the artifact, the conversation is the delivery.
+Save the pack in the archive folder derived in Step 1 as `interview_prep_<stage>.md` (create the folder if this application predates `/outcome`). The folder is gitignored, so the pack stays personal; one file per stage, so earlier packs remain as history. Present the pack in chat as well - the file is the artifact, the conversation is the delivery.
 
 ---
 
@@ -104,6 +104,6 @@ If Step 3 drafted new STAR answers the user approved for keeps, remind them thos
 2. **Honesty on gaps.** Weak matches get bridge answers (acknowledge → adjacent experience → learning path), never invented experience. Same rule as everywhere else in this repo.
 3. **Verified research only.** Company specifics go in the pack only after independent confirmation. Interviewer notes stick to public professional information.
 4. **Stage-appropriate prep.** A phone screen pack and a final-round pack are different documents; recorded feedback from earlier stages takes priority over generic question lists.
-5. **Write only to the application archive** — with one exception. The prep pack lands in `documents/applications/<company>_<role>/`; framework files are not edited, except appending user-approved STAR examples to `07-interview-prep.md` on explicit request.
+5. **Write only to the application archive** — with one exception. The prep pack lands in the archive folder derived in Step 1; framework files are not edited, except appending user-approved STAR examples to `07-interview-prep.md` on explicit request.
 
    **The exception is `01-candidate-profile.md`.** Interview prep is where new facts surface most often: the user recalls a metric, corrects a scope, or fills in a STAR stub. When that happens, write the fact into the profile, as well as putting it in the prep pack. A fact recorded only in prep material reads as unsupported to a later drafting session and gets stripped from CVs as a fabrication. Prep files are not a substitute for the profile.