feat: replace fish integration files with built-in fish subcommand (task u6)

Add `foostore fish` subcommand that prints the complete fish shell integration
script (tab completions for foostore + the ge wrapper function) to stdout so
users can source it with `foostore fish | source`. Remove install-fish.sh,
FISH_INTEGRATION.md, and completions/ directory. Update CLAUDE.md and README.md
to document the new workflow.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 0 insertions, 89 deletions

diff --git a/FISH_INTEGRATION.md b/FISH_INTEGRATION.md
deleted file mode 100644
index c1e7aee..0000000
--- a/FISH_INTEGRATION.md
+++ /dev/null
@@ -1,89 +0,0 @@
-# Fish Shell Integration for foostore
-
-## Installation
-
-### Automatic Installation
-
-```bash
-cd /home/paul/git/foostore
-./install-fish.sh
-```
-
-### Manual Installation
-
-1. Copy the completion file for `foostore`:
-```bash
-cp completions/foostore.fish ~/.config/fish/completions/
-```
-
-2. Copy the wrapper function for `ge`:
-```bash
-cp completions/ge.fish ~/.config/fish/functions/
-```
-
-3. Reload fish shell:
-```bash
-exec fish
-```
-
-## Usage
-
-### `foostore` command
-
-The `foostore` command now has full tab completion:
-- Tab complete all subcommands (ls, search, cat, paste, etc.)
-- Tab complete file paths for `import`
-- Tab complete the `force` flag for import
-
-### `ge` wrapper
-
-The `ge` wrapper provides shortcuts:
-
-```bash
-# Interactive mode (no arguments)
-ge
-
-# Search shortcut (if not a known command, treats as search)
-ge mypassword
-# Same as: foostore search mypassword
-
-# Explicit commands still work
-ge cat mypassword
-ge import file.txt backup/
-ge import file.txt backup/ force
-```
-
-In interactive mode, empty `Enter` opens the fuzzy picker with direct action keys:
-- `Enter` select
-- `Ctrl-T` cat
-- `Ctrl-Y` paste
-- `Ctrl-O` open
-- `Ctrl-E` edit
-
-The picker preview remains metadata-only for safety (no decrypted secret preview).
-
-### Dynamic Entry Completion
-
-For better security, entry completion only works when the `PIN` environment variable is set:
-
-```bash
-# Set PIN for session (entries will autocomplete)
-set -x PIN yourpin
-
-# Use foostore with autocomplete
-ge <TAB>
-
-# Unset PIN when done
-set -e PIN
-```
-
-Without `PIN` set, commands will still autocomplete, but entry names won't (to avoid prompting for PIN during tab completion).
-
-## Features
-
-- ✓ Dynamic command completion (fetched from `foostore commands`)
-- ✓ Smart search fallback in `ge` wrapper
-- ✓ Entry name completion (when PIN is set)
-- ✓ File path completion for import/export
-- ✓ Force flag completion
-- ✓ No hardcoded command lists (stays in sync with foostore updates)